feat(ack): liste unique des services acked

icingabot.py

@@ -308,7 +308,7 @@ class IcingaBot(Icinga2ServiceManager, irc.bot.SingleServerIRCBot):
                 self.send(
                     "Acknowledged ({}): {}".format(
                         len(acknowledged),
-                        ', '.join([s["attrs"]["display_name"] for s in acknowledged])
+                        ', '.join({s["attrs"]["display_name"] for s in acknowledged})
                     )
                 )
         else: