Merge branch '5.1' into 5.2

* 5.1:
  Update DSN

Author: OskarStark

notifier.rst

@@ -139,11 +139,12 @@ integration with these chat services:
 
 ==========  ================================  ===========================================================================
 Service     Package                           DSN
+<<<<<<< HEAD
 ==========  ================================  ===========================================================================
 Discord     ``symfony/discord-notifier``      ``discord://TOKEN@default?webhook_id=ID``
 GoogleChat  ``symfony/google-chat-notifier``  ``googlechat://ACCESS_KEY:ACCESS_TOKEN@default/SPACE?threadKey=THREAD_KEY``
 LinkedIn    ``symfony/linked-in-notifier``    ``linkedin://TOKEN:USER_ID@default``
-Mattermost  ``symfony/mattermost-notifier``   ``mattermost://TOKEN@ENDPOINT?channel=CHANNEL``
+Mattermost  ``symfony/mattermost-notifier``   ``mattermost://ACCESS_TOKEN@HOST/PATH?channel=CHANNEL``
 RocketChat  ``symfony/rocket-chat-notifier``  ``rocketchat://TOKEN@ENDPOINT?channel=CHANNEL``
 Slack       ``symfony/slack-notifier``        ``slack://TOKEN@default?channel=CHANNEL``
 Telegram    ``symfony/telegram-notifier``     ``telegram://TOKEN@default?channel=CHAT_ID``