gui: Convert URLs in warning messages to HTML links (fixes #3241)

Skip-check: metalint (annoying timeout)

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3747

gui/default/syncthing/app.js

@@ -10,7 +10,7 @@
 
 var syncthing = angular.module('syncthing', [
     'angularUtils.directives.dirPagination',
-    'pascalprecht.translate',
+    'pascalprecht.translate', 'ngSanitize',
 
     'syncthing.core'
 ]);