Prevents fade-in of modal forms in case of

existing previous modal form.
Note: This is just a quick fix for the problem specified in the bug.
In general there are problems with using overlaying modals.
Each subsequent modal form doesn't 'backdrop' the previous one,
and the first modal could be closed without closing the last one.

Fixes bug 944502

Change-Id: I8086dcd14f5fbfb3c9d69a7f2f20e62e012b294e

horizon/static/horizon/js/horizon.js

@@ -61,8 +61,9 @@ var Horizon = function() {
     action_string = $action.text();
     title = "Confirm " + action_string;
     body = "Please confirm your selection. This action cannot be undone.";
+    var use_backdrop = $('.modal').length == 0; // check if already has a modal
     modal = horizon.modals.create(title, body, action_string);
-    modal.modal('show');
+    modal.modal({backdrop: use_backdrop});
     modal.find('.btn-primary').click(function (evt) {
       form = $action.closest('form');
       form.append("<input type='hidden' name='" + $action.attr('name') + "' value='" + $action.attr('value') + "'/>");