v1.10.0 don't show two spinners for Sign In + Register (bug 1130583)

bower.json

@@ -1,7 +1,7 @@
 {
   "author": "Mozilla",
   "name": "marketplace-core-modules",
-  "version": "1.9.0",
+  "version": "1.10.0",
   "ignore": [
     "bower.json",
     "LICENSE",

login.js

@@ -84,6 +84,7 @@ define('login',
         e.preventDefault();
 
         var $this = $(this);
+        $('.loading-submit').removeClass('loading-submit');
         $this.addClass('loading-submit');
         startLogin({register: $this.hasClass('register')}).always(function() {
             $this.removeClass('loading-submit').trigger('blur');