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 846f3be..672cebf 100644
--- a/tempest/api/compute/servers/test_create_server.py
+++ b/tempest/api/compute/servers/test_create_server.py
@@ -165,9 +165,8 @@
         msg = None
         if not utils.get_service_list()['volume']:
             msg = "Volume service not enabled."
-        # The tests are not launched in upstream and not working with Ironic
-        if (hasattr(CONF.service_available, 'ironic') and
-            CONF.service_available.ironic):
-            msg = "Volume tests are not available for ironic."
+        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)