CMFActivity.Activity: Do not check message presence when registered.

This should never match, because published API does not provide access to
Message when registering it (this is intentional).
Also, this search is O(n), which makes activity creation complexity
O(n**2).

product/CMFActivity/Activity/Queue.py

@@ -241,10 +241,7 @@ class Queue(object):
     return m in message_list
 
   def registerMessage(self, activity_buffer, activity_tool, m):
-    message_list = activity_buffer.getMessageList(self)
-    if m in message_list:
-      return
-    message_list.append(m)
+    activity_buffer.getMessageList(self).append(m)
     m.is_registered = True
 
   def unregisterMessage(self, activity_buffer, activity_tool, m):

product/CMFActivity/Activity/SQLDict.py

@@ -105,8 +105,7 @@ class SQLDict(SQLBase):
     if message_id in uid_set:
       return
     uid_set.add(message_id)
-    activity_buffer.getMessageList(self).append(m)
-    m.is_registered = True
+    super(SQLDict, self).registerMessage(activity_buffer, activity_tool, m)
 
   def unregisterMessage(self, activity_buffer, activity_tool, m):
     m.is_registered = False # This prevents from inserting deleted messages into the queue