[qutebrowser] New notificaitons for mailhog

qutebrowser/.config/qutebrowser/autoconfig.yml

@@ -29,9 +29,10 @@ settings:
     https://meet.google.com: true
     https://modernatx.webex.com: true
     https://teams.microsoft.com: true
-  content.notifications.enabled:
+  content.notifications:
     https://15five.lightning.force.com: true
     https://app.slack.com: true
+    https://mailhog.unbl.ink: true
     https://media.unbl.ink: true
   content.register_protocol_handler:
     https://calendar.google.com?cid=%25s: true