do not accept /topicX

src/groupchat_window.py

@@ -586,6 +586,9 @@ class GroupchatWindow(chat.Chat):
 				# or /topic to get the subject printed
 				after_command = message[6:] # 6 is len('/topic')
 				splitted_arg = after_command.split()
+				if not message[6].isspace() and len(message) > 6:
+					# he wrote /topicA so do not accept that
+					return
 				if len(splitted_arg): # we set subject
 					new_subj = ' '.join(splitted_arg).strip()
 					gajim.connections[self.account].send_gc_subject(room_jid,