Description of problem:
Add a managed SD on HP3PAR fails with:

2019-02-03 14:42:28,673+02 INFO  [org.ovirt.engine.core.common.utils.cinderlib.CinderlibExecutor] (default task-6) [f2232630-86e2-41db-80bf-e5f0586b46bf] cinderlib output: /usr/lib/python2.7/site-packages/paramiko/kex_ecdh_nist.py:39: CryptographyDeprecationWarning: encode_point has been deprecated on EllipticCurvePublicNumbers and will be removed in a future version. Please use EllipticCurvePublicKey.public_bytes to obtain both compressed and uncompressed point encoding.
  m.add_string(self.Q_C.public_numbers().encode_point())
/usr/lib/python2.7/site-packages/paramiko/kex_ecdh_nist.py:96: CryptographyDeprecationWarning: Support for unsafe construction of public numbers from encoded data will be removed in a future version. Please use EllipticCurvePublicKey.from_encoded_point
  self.curve, Q_S_bytes
/usr/lib/python2.7/site-packages/paramiko/kex_ecdh_nist.py:111: CryptographyDeprecationWarning: encode_point has been deprecated on EllipticCurvePublicNumbers and will be removed in a future version. Please use EllipticCurvePublicKey.public_bytes to obtain both compressed and uncompressed point encoding.
  hm.add_string(self.Q_C.public_numbers().encode_point())
{"driver_version": "4.0.2", "replication_enabled": false, "replication_targets": [], "array_id": 139115, "pools": [{"thick_provisioning_support": true, "bandwidth": null, "consistent_group_snapshot_enabled": true, "latency": null, "filter_function": null, "compression": true, "total_volumes": 17, "consistent_group_replication_enabled": false, "free_capacity_gb": 7134, "queue_length": null, "backend_state": "up", "pool_name": "O", "goodness_function": null, "multiattach": false, "provisioned_capacity_gb": 40, "thin_provisioning_support": true, "io_size": null, "reserved_percentage": 15, "QoS_support": true, "capacity_utilization": 0.23772898895259406, "total_capacity_gb": 7151, "location_info": "HPE3PARDriver:CZ3836C3RB:O", "avg_busy_perc": null, "throughput": null, "max_over_subscription_ratio": "20.0"}], "vendor_name": "Hewlett Packard Enterprise", "volume_backend_name": "cinder-hp3par", "storage_protocol": "iSCSI"}
2019-02-03 14:42:28,682+02 ERROR [org.ovirt.engine.core.bll.storage.domain.GetManagedBlockStorageStatsCommand] (default task-6) [f2232630-86e2-41db-80bf-e5f0586b46bf] Failed to fetch Managed block storage stats, output: '/usr/lib/python2.7/site-packages/paramiko/kex_ecdh_nist.py:39: CryptographyDeprecationWarning: encode_point has been deprecated on EllipticCurvePublicNumbers and will be removed in a future version. Please use EllipticCurvePublicKey.public_bytes to obtain both compressed and uncompressed point encoding.
  m.add_string(self.Q_C.public_numbers().encode_point())
/usr/lib/python2.7/site-packages/paramiko/kex_ecdh_nist.py:96: CryptographyDeprecationWarning: Support for unsafe construction of public numbers from encoded data will be removed in a future version. Please use EllipticCurvePublicKey.from_encoded_point
  self.curve, Q_S_bytes
/usr/lib/python2.7/site-packages/paramiko/kex_ecdh_nist.py:111: CryptographyDeprecationWarning: encode_point has been deprecated on EllipticCurvePublicNumbers and will be removed in a future version. Please use EllipticCurvePublicKey.public_bytes to obtain both compressed and uncompressed point encoding.
  hm.add_string(self.Q_C.public_numbers().encode_point())



Version-Release number of selected component (if applicable):
ovirt-engine : 4.3.0.2-0.1.el7
CinderLib: 0.3.5

How reproducible:
100%

Steps to Reproduce:
1.Add via REST HP3PAR storage domain:

request:
<storage_domain>
   <name>cinder-hp3par</name>
   <type>managed_block_storage</type>
   <storage>
      <type>managed_block_storage</type>
      <driver_options>
      	<property>
            <name>hpe3par_api_url</name>
            <value>https://3par-cli.mgmt.lab3.tlv.redhat.com:8080/api/v1</value>
         </property>
      	<property>
            <name>san_ip</name>
            <value>10.35.84.14</value>
         </property>
      	<property>
            <name>san_login</name>
            <value>admin</value>
         </property>
         <property>
            <name>san_password</name>
            <value>Qum!0net</value>
         </property>
         <property>
            <name>hpe3par_username</name>
            <value>3paredit</value>
         </property>
         <property>
            <name>hpe3par_password</name>
            <value>123456</value>
         </property>
         <property>
            <name>hpe3par_cpg</name>
            <value>O</value>
         </property>
         <property>
            <name>volume_driver</name>
            <value>cinder.volume.drivers.hpe.hpe_3par_fc.HPE3PARFCDriver</value>
         </property>
         <property>
            <name>hpe3par_debug</name>
            <value>False</value>
         </property>
         <property>
            <name>hpe3par_iscsi_chap_enabled</name>
            <value>False</value>
         </property>
         <property>
            <name>hpe3par_snapshot_retention</name>
            <value>48</value>
         </property>
         <property>
            <name>hpe3par_snapshot_expiration</name>
            <value>72</value>
         </property>
         <property>
            <name>max_over_subscription_ratio</name>
            <value>20.0</value>
         </property>
         <property>
            <name>reserved_percentage</name>
            <value>15</value>
         </property>
      </driver_options>
   </storage>
   <host>
      <name>host_mixed_1</name>
   </host>
</storage_domain>


Actual results:
Add SD fails with CryptographyDeprecationWarning errors.

Expected results:
Add SD works without this error.

Additional info: