removing WATCHTOWER_NOTIFICATIONS as this is Legacy notifications

docs/examples.md

@@ -161,7 +161,6 @@ services:
   watchtower:
     image: containrrr/watchtower
     environment:
-      - WATCHTOWER_NOTIFICATIONS=shoutrrr
       - WATCHTOWER_NOTIFICATION_SKIP_TITLE=True
       - WATCHTOWER_NOTIFICATION_URL=ntfy://ntfy.sh/my_watchtower_topic?title=WatchtowerUpdates
 ```