default.xml: Remove reference to booting.oniroproject.org for chat

Forwarded: !283
Relate-to: #787


Signed-off-by: Philippe Coval <philippe.coval.ext@huawei.com>

manifests/default.xml

@@ -12,8 +12,9 @@ SPDX-FileCopyrightText: Huawei Inc.
 
 		Check out Oniro Project documentation at https://docs.oniroproject.org
 
-		Meet the developers on mattermost at https://chat.booting.oniroproject.org/ or
-		point your favorite IRC client to the #oniro channel on https://libera.chat
+		Chat with community in Oniro online's IRC channel as explained at:
+		https://docs.oniroproject.org/en/latest/community-chat-platform.html
+		or directly join to the #oniro channel at https://libera.chat
 
 	</notice>