Hot fix for the TF clouds for 'mtu' field

At some TF2011 clouds, it is not possible to set the MTU while
creating the network, the mtu field is not ignored, but causes
the '400 Bad request' error.
For this, the hot fix is created to set this field during VM
creation only at OVS clouds.

Related-PROD: PROD-36943

Change-Id: I6f4bb66bafdee0f2d2957243765870b34db93823
diff --git a/utils/os_client.py b/utils/os_client.py
index aa51732..6694813 100644
--- a/utils/os_client.py
+++ b/utils/os_client.py
@@ -398,7 +398,9 @@
                 'project_id': project_id
             }
         }
-        if mtu != 'default':
+        # in TF2011 we cannot set MTU while creating the net: 400 Bad request
+        # error can happen with 'mtu' field, so we update mtu of ports later
+        if (mtu != 'default') and (not self.is_cloud_tf()):
             try:
                 net_body['network']['mtu'] = int(mtu)
             except ValueError as e: