fix npe w/ prev commit

cms/templates/login.html

@@ -78,7 +78,7 @@
       function(json) {
         if(json.success) {
           var next = /next=([^&]*)/g.exec(decodeURIComponent(window.location.search));
-          if (next.length > 1) {
+          if (next && next.length > 1) {
             location.href = next[1];
           }
           else location.href = "${reverse('homepage')}";