[FIX] web_editor: link creation: @ not necessarily a mailto

In the field HTML, click on create hyperlink
as its url, put in http://hell-broke-luce.waits/?param=tom@waits.com

Before this commit, since the url merely contains a @, it was considered as a mailto: link

After this commit, if the url starts with a flavor of http, it is considered
as a standard http link

OPW 1869087
closes #26012

addons/web_editor/static/src/js/widgets/widgets.js

@@ -1519,7 +1519,7 @@ var LinkDialog = Dialog.extend({
             + ((size && size.length) ? (' btn-' + size) : '');
         var isNewWindow = this.$('input[name="is_new_window"]').prop('checked');
 
-        if (url.indexOf('@') >= 0 && url.indexOf('mailto:') < 0) {
+        if (url.indexOf('@') >= 0 && url.indexOf('mailto:') < 0 && !url.match(/^http[s]?/i)) {
             url = ('mailto:' + url);
         }
         return {