Description of problem:
If host/guest mapping info updated, restart virt-who service will result in failed to communicate with subscription-manager.

Version-Release number of selected component (if applicable):
virt-who-0.16-7.el6.noarch
subscription-manager-1.16.8-8.el6.x86_64
python-rhsm-1.16.6-1.el6.x86_64
Satellite-6.1.0-RHEL-6-20160321

How reproducible:
20%

Steps to Reproduce:
1. Register system to satellite6.1
2. Configure virt-who run at rhevm mode and restart virt-who service
[root@hp-dl360g6-01 ~]# cat /etc/sysconfig/virt-who  | grep -v ^# | grep -v ^$
VIRTWHO_DEBUG=1
VIRTWHO_RHEVM=1
VIRTWHO_RHEVM_OWNER=ACME_Corporation
VIRTWHO_RHEVM_ENV=Library
VIRTWHO_RHEVM_SERVER=https://dell-pe1955-01.rhts.eng.bos.redhat.com:443
VIRTWHO_RHEVM_USERNAME=admin@internal
VIRTWHO_RHEVM_PASSWORD=redhat
[root@hp-dl360g6-01 ~]# service virt-who restart
3. In the rhevm webUI,stop vm, then remove host, restart virt-who service and check virt-who's log.
[root@hp-dl360g6-01 ~]# tail -f /var/log/rhsm/rhsm.log
2016-03-31 05:34:27,114 [virtwho.main DEBUG] MainProcess(8258):MainThread @virtwho.py:terminate:359 - virt-who is shutting down
2016-03-31 05:34:27,552 [virtwho.env_cmdline DEBUG] RhevM-1(8265):MainThread @virt.py:run:381 - Virt backend 'env/cmdline' terminated
2016-03-31 05:34:28,117 [virtwho.main ERROR] MainProcess(8258):MainThread @virtwho.py:send:216 - Error in communication with subscription manager:
Traceback (most recent call last):
  File "/usr/share/virt-who/virtwho.py", line 199, in send
    self._sendGuestAssociation(report)
  File "/usr/share/virt-who/virtwho.py", line 226, in _sendGuestAssociation
    manager.hypervisorCheckIn(report, self.options)
  File "/usr/share/virt-who/manager/subscriptionmanager/subscriptionmanager.py", line 163, in hypervisorCheckIn
    is_async = hasattr(self.connection, 'has_capability') and self.connection.has_capability('hypervisors_async')
  File "/usr/lib64/python2.6/site-packages/rhsm/connection.py", line 868, in has_capability
    self.capabilities = self._load_manager_capabilities()
  File "/usr/lib64/python2.6/site-packages/rhsm/connection.py", line 850, in _load_manager_capabilities
    status = self.getStatus()
  File "/usr/lib64/python2.6/site-packages/rhsm/connection.py", line 1335, in getStatus
    return self.conn.request_get(method)
  File "/usr/lib64/python2.6/site-packages/rhsm/connection.py", line 681, in request_get
    return self._request("GET", method)
  File "/usr/lib64/python2.6/site-packages/rhsm/connection.py", line 571, in _request
    conn.request(request_type, handler, body=body, headers=headers)
  File "/usr/lib64/python2.6/httplib.py", line 936, in request
    self._send_request(method, url, body, headers)
  File "/usr/lib64/python2.6/httplib.py", line 973, in _send_request
    self.endheaders()
  File "/usr/lib64/python2.6/httplib.py", line 930, in endheaders
    self._send_output()
  File "/usr/lib64/python2.6/httplib.py", line 802, in _send_output
    self.send(msg)
  File "/usr/lib64/python2.6/httplib.py", line 761, in send
    self.connect()
  File "/usr/lib64/python2.6/site-packages/M2Crypto/httpslib.py", line 73, in connect
    raise error
error: [Errno 4] Interrupted system call
2016-03-31 05:34:28,128 [virtwho.main DEBUG] MainProcess(8258):MainThread @virtwho.py:send_report:168 - Report from "env/cmdline" failed to sent
2016-03-31 05:34:28,130 [virtwho.main DEBUG] MainProcess(8258):MainThread @virtwho.py:<module>:824 - virt-who terminated

Actual results:
Failed to communicate with subscription-manager when stop virt-who service as "Interrupted system call"

Expected results:
It shouldn't show error info when stop virt-who service

Additional info: