check master connection is not None before trying to send message

git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@171 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/client/handler.py

@@ -84,6 +84,7 @@ class ClientEventHandler(EventHandler):
             if isinstance(node, StorageNode):
                 # Notify primary master node that a storage node is temporarily down
                 conn = app.master_conn
+                if conn is not None:
                     conn.lock()
                     try:
                         p = Packet()
@@ -111,6 +112,7 @@ class ClientEventHandler(EventHandler):
             if isinstance(node, StorageNode):
                 # Notify primary master node that a storage node is temporarily down
                 conn = app.master_conn
+                if conn is not None:
                     conn.lock()
                     try:
                         p = Packet()
@@ -138,6 +140,7 @@ class ClientEventHandler(EventHandler):
             if isinstance(node, StorageNode):
                 # Notify primary master node that a storage node is broken
                 conn = app.master_conn
+                if conn is not None:
                     conn.lock()
                     try:
                         p = Packet()