[FIX] web_editor: allow editing t-field links

There is a hackish feature in the web_editor which forces the
contenteditable to true on links which are clicked and removes it
anywhere else in the page so that only the link is editable after
click. This allows to add text at the end of a link without adding it
outside of the link by mistake.

The feature was badly implemented because, if the link was editable
without having any parent which is editable, the contenteditable was
forced to true, then immediatly forced to false when forcing to false
every page element. This was the case for lots of t-field. By example
the product categories in eCommerce are t-field links which are in non
editable <li/> elements...

addons/web_editor/static/src/js/rte.js

@@ -516,7 +516,7 @@ var RTE = Widget.extend({
             // add contenteditable on link to improve its editing behaviour
             $target.attr('contenteditable', true);
             setTimeout(function () {
-                $editable.attr('contenteditable', false);
+                $editable.not($target).attr('contenteditable', false);
             });
             // once clicked outside, remove contenteditable on link
             var reactive_editable = function(e){