erp5_json_form: changestate mutex added on getContent for preventing data loss on save

bt5/erp5_json_form/SkinTemplateItem/portal_skins/erp5_json_form/jsonform.gadget.js.js

@@ -675,6 +675,6 @@
           });
       }
       return {};
-    });
+    }, {mutex: 'changestate'});
 
 }(window, document, location, rJS, RSVP, jIO, tv4));
\ No newline at end of file