skip ServersTestBootFromVolume test in case of ceph deployment.

Because of the fact that ironic supports only iscsi or fibre_channel
back ends it means if an environment is deployed with Ceph the
following test ServersTestBootFromVolume)' in this particular
deployment have to be skipped.

Change-Id: Ie493578dea0bb92d7952de86bbe7cb5018048bb2
Related-prod: PROD-27396
diff --git a/tempest/api/compute/servers/test_create_server.py b/tempest/api/compute/servers/test_create_server.py
index c660821..4f1e3c3 100644
--- a/tempest/api/compute/servers/test_create_server.py
+++ b/tempest/api/compute/servers/test_create_server.py
@@ -157,6 +157,11 @@
     @classmethod
     def skip_checks(cls):
         super(ServersTestBootFromVolume, cls).skip_checks()
+        msg = None
         if not utils.get_service_list()['volume']:
             msg = "Volume service not enabled."
+        if (getattr(CONF.service_available, 'ironic', False) and
+                CONF.volume.storage_protocol == 'ceph'):
+            msg = "Volume tests are not available for Ironic with Ceph."
+        if msg is not None:
             raise cls.skipException(msg)