matrix: Remove (IRC) from display names

roles/matrix/templates/irc-bridge.yaml.j2

@@ -268,7 +268,7 @@ ircService:
         # $NICK somewhere in it if it is specified. Can also use $SERVER to
         # insert the IRC domain.
         # Optional. Default: "$NICK (IRC)". Example: "Alice (IRC)"
-        displayName: "$NICK (IRC)"
+        displayName: "$NICK"
         # Number of tries a client can attempt to join a room before the request
         # is discarded. You can also use -1 to never retry or 0 to never give up.
         # Optional. Default: -1