fix(ionicConfig): allow using tel for hrefs

Closes #3647

Author: mhartington

js/angular/service/ionicConfig.js

@@ -628,6 +628,6 @@ IonicModule
 // http://blogs.msdn.com/b/msdn_answers/archive/2015/02/10/
 // running-cordova-apps-on-windows-and-windows-phone-8-1-using-ionic-angularjs-and-other-frameworks.aspx
 .config(['$compileProvider', function($compileProvider) {
-  $compileProvider.aHrefSanitizationWhitelist(/^\s*(https?|ftp|mailto|file|ghttps?|ms-appx|x-wmapp0):/);
-  $compileProvider.imgSrcSanitizationWhitelist(/^\s*(https?|ftp|file|ms-appx|x-wmapp0):|data:image\//);
+  $compileProvider.aHrefSanitizationWhitelist(/^\s*(https?|tel|ftp|mailto|file|ghttps?|ms-appx|x-wmapp0):/);
+  $compileProvider.imgSrcSanitizationWhitelist(/^\s*(https?|tel|ftp|file|ms-appx|x-wmapp0):|data:image\//);
 }]);