Description of problem:
Sending an empty description field when creating a new storage domain results
in an error about the description field being too long!


Version-Release number of selected component (if applicable):
ovirt-engine-restapi-4.2.5.2-0.1.el7ev.noarch


How reproducible:
Always


Steps to Reproduce:
'/usr/bin/curl' -k --header 'Accept: application/json' --request 'POST' --header 'Content-Type: application/xml' --data '
<storage_domain>
  <name>Newe Storage Domain</name>
  <comment>60002ac0000000000000000a00021e55</comment>
  <description></description>
  <discard_after_delete>true</discard_after_delete>
  <type>data</type>
  <host>
    <name>hostname</name>
  </host>
  <storage>
    <type>fcp</type>
    <volume_group>
      <logical_units>
        <logical_unit id="360002ac0000000000000000a00021e55"/>
      </logical_units>
    </volume_group>
  </storage>
</storage_domain>
' --negotiate -u ':' 'https://rhvm.example.com/ovirt-engine/api/storagedomains'  2>/dev/null



Actual results:
Output of the curl command:
$VAR1 = {
          'detail' => '[Storage Domain description must not exceed 4000 characters, Attribute: privateStorageDomain.description]',
          'reason' => 'Operation Failed'
        };



Expected results:
Storage domain to be created without description


Additional info:
n.a.