Fix topo check when no hosts have benn discovered yet

Change-Id: I355c88e530270ea0a6394c8134536abb9bd6d97b
diff --git a/TestON/tests/HAclusterRestart/HAclusterRestart.py b/TestON/tests/HAclusterRestart/HAclusterRestart.py
index 2677b8d..f9ab800 100644
--- a/TestON/tests/HAclusterRestart/HAclusterRestart.py
+++ b/TestON/tests/HAclusterRestart/HAclusterRestart.py
@@ -2286,6 +2286,8 @@
                     currentHostsResult = main.Mininet1.compareHosts(
                             mnHosts,
                             hosts[ controller ] )
+                elif hosts[ controller ] == []:
+                    currentHostsResult = main.TRUE
                 else:
                     currentHostsResult = main.FALSE
                 utilities.assert_equals( expect=main.TRUE,
@@ -2400,7 +2402,7 @@
         consistentHostsResult = main.TRUE
         for controller in range( len( hosts ) ):
             controllerStr = str( controller + 1 )
-            if hosts[ controller ] and "Error" not in hosts[ controller ]:
+            if hosts[ controller ] is not None and "Error" not in hosts[ controller ]:
                 if hosts[ controller ] == hosts[ 0 ]:
                     continue
                 else:  # hosts not consistent