Omit warning message regarding non-anonymous room

Previous versions of XEP-0045 suggested sending a warning message to new
occupants of a non-anonymous MUC room.  The current revision (1.25) says
that a status code of "100" must be returned with the user's initial
presence, instead.  We already do this (in addition to generating the
warning message).

Receiving the warning message each time the client joins the room can
become annoying, especially when reconnections occur frequently (e.g.,
on mobile devices).  So, we omit it, now.

src/mod_muc_room.erl

@@ -1853,31 +1853,6 @@ add_new_user(From, Nick,
 		NewState = add_user_presence(From, Packet,
 					     add_online_user(From, Nick, Role,
 							     StateData)),
-		if not (NewState#state.config)#config.anonymous ->
-		       WPacket = #xmlel{name = <<"message">>,
-					attrs = [{<<"type">>, <<"groupchat">>}],
-					children =
-					    [#xmlel{name = <<"body">>,
-						    attrs = [],
-						    children =
-							[{xmlcdata,
-							  translate:translate(Lang,
-									      <<"This room is not anonymous">>)}]},
-					     #xmlel{name = <<"x">>,
-						    attrs =
-							[{<<"xmlns">>,
-							  ?NS_MUC_USER}],
-						    children =
-							[#xmlel{name =
-								    <<"status">>,
-								attrs =
-								    [{<<"code">>,
-								      <<"100">>}],
-								children =
-								    []}]}]},
-		       ejabberd_router:route(StateData#state.jid, From, WPacket);
-		   true -> ok
-		end,
 		send_existing_presences(From, NewState),
 		send_new_presence(From, NewState),
 		Shift = count_stanza_shift(Nick, Els, NewState),