Prevent angular from throwing exceptions if error is null

src/js/index.js

@@ -417,6 +417,8 @@ app.filter('taskName', function () {
 
 app.filter('errorSuggestion', function () {
     return function (error) {
+        if (!error) return '';
+
         switch (error.reason) {
         case ERROR.ACCESS_DENIED:
             if (error.domain) return 'Check the DNS credentials of ' + error.domain.domain + ' in the Domains & Certs view';