Task #8571: Replaced very modern python expression by more obsolete set...

Task #8571: Replaced very modern python expression by more obsolete set expression so that primitive machines can handle this

LCS/Messaging/python/messaging/messages.py

@@ -47,7 +47,7 @@ def validate_qpid_message(qmsg):
     :raises InvalidMessage: if any of the required properties are missing in
     the Qpid message
     """
-    required_props = {"SystemName", "MessageType", "MessageId"}
+    required_props = set(["SystemName", "MessageType", "MessageId"])
     if not isinstance(qmsg, qpid.messaging.Message):
         raise InvalidMessage(
             "Not a Qpid Message: %r" % type(qmsg)
@@ -208,7 +208,7 @@ class LofarMessage(object):
         """
         return list(
             _QPID_MESSAGE_FIELDS.union(self._qpid_msg.properties) -
-            {'properties'}
+            set(['properties'])
         )
 
     @property