Only handle event if it belongs to the control

gajim/groupchat_control.py

@@ -2020,6 +2020,10 @@ class GroupchatControl(ChatControlBase):
     def _message_sent(self, obj):
         if not obj.message:
             return
+        if obj.account != self.account:
+            return
+        if obj.jid != self.room_jid:
+            return
         # we'll save sent message text when we'll receive it in
         # _nec_gc_message_received
         self.last_sent_msg = obj.stanza_id