Add valid codes for redfish call to network interface

Acceptable response code 200 and 204.

Change-Id: Ic6f412c5a8d17c93a8b59e55a78aa91a93631628
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/lib/bmc_network_utils.robot b/lib/bmc_network_utils.robot
index 337aef6..6468ce9 100644
--- a/lib/bmc_network_utils.robot
+++ b/lib/bmc_network_utils.robot
@@ -256,6 +256,7 @@
 
     ${data}=  Create Dictionary  HostName=${hostname}
     Redfish.patch  ${REDFISH_NW_PROTOCOL_URI}  body=&{data}
+    ...  valid_status_codes=[${HTTP_OK}, ${HTTP_NO_CONTENT}]
 
 
 Verify IP On BMC