Description of problem:
Virt-who can't get connect rhevm4.0 api url result in virt-who failed to get h/g mapping info when monitor rhevm4.0.

Version-Release number of selected component (if applicable):
rhevm-4.0.0.4-0.1.el7ev.noarch
rhev-hypervisor7-ng-4.0-20160609.0
virt-who-0.14-9.el7.noarch

How reproducible:
Always

Steps to Reproduce:
1. On rhevm4.0 webUI, add rhev-hypervisor7-ng-4.0-20160609.0 to rhevm-4.0.0.4-0.1.el7ev.noarch.
2. Register rhevh to satellite6.2
3. Configure virt-who run at rhevm mode and restart virt-who service
[root@bootp-73-5-249 ~]# 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://hp-z220-04.qe.lab.eng.nay.redhat.com:443/ovirt-engine/
VIRTWHO_RHEVM_USERNAME=admin@internal
VIRTWHO_RHEVM_PASSWORD=redhat

[root@bootp-73-5-249 ~]# service virt-who restart && tail -f /var/log/rhsm/rhsm.log 
2016-06-14 02:36:55,177 [INFO]  @virt.py:317 - Waiting 3600 seconds before retrying backend 'env/cmdline'
2016-06-14 02:49:31,858 [INFO]  @virtwho.py:697 - Using configuration "env/cmdline" ("rhevm" mode)
2016-06-14 02:49:31,859 [DEBUG]  @virtwho.py:216 - Starting infinite loop with 3600 seconds interval
2016-06-14 02:49:31,954 [ERROR]  @virt.py:306 - Virt backend 'env/cmdline' fails with exception:
Traceback (most recent call last):
  File "/usr/share/virt-who/virt/virt.py", line 301, in run
    self._run()
  File "/usr/share/virt-who/virt/virt.py", line 332, in _run
    report = self._get_report()
  File "/usr/share/virt-who/virt/virt.py", line 274, in _get_report
    return HostGuestAssociationReport(self.config, self.getHostGuestMapping())
  File "/usr/share/virt-who/virt/rhevm/rhevm.py", line 104, in getHostGuestMapping
    clusters_xml = ElementTree.parse(self.get(self.clusters_url))
  File "/usr/share/virt-who/virt/rhevm/rhevm.py", line 89, in get
    return urllib2.urlopen(request)
  File "/usr/lib64/python2.7/urllib2.py", line 154, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib64/python2.7/urllib2.py", line 437, in open
    response = meth(req, response)
  File "/usr/lib64/python2.7/urllib2.py", line 550, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib64/python2.7/urllib2.py", line 475, in error
    return self._call_chain(*args)
  File "/usr/lib64/python2.7/urllib2.py", line 409, in _call_chain
    result = func(*args)
  File "/usr/lib64/python2.7/urllib2.py", line 558, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
HTTPError: HTTP Error 404: Not Found
2016-06-14 02:49:31,956 [INFO]  @virt.py:317 - Waiting 3600 seconds before retrying backend 'env/cmdline'


Actual results:
Virt-who failed to get host/guest mapping info.

Expected results:
Virt-who should get host/guest mapping info successfully. 

Additional info: