Fixed the looping bug on killed thread

shoutbox.py

@@ -117,10 +117,11 @@ class Shoutbox(object):
                                 logging.info(f"matched {event.__name__}")
                                 callback(message)
                 # kill afk clients
-                for c in self.irc_clients.values():
+                for k, c in self.irc_clients.items():
                     if datetime.datetime.now() - c[1] > datetime.timedelta(hours=1):
                         logging.info(f"killing {c[0].nick}")
                         c[0].stop()
+                        self.irc_clients.pop(k)
             except Exception as e:
                 logging.error(f"Faillure in Shoutbox thread {e}")
             finally: