check if given selected value is a 0, if it is a zero so return it as

string to prevent that jquery think its a boolean

Author: Falseee

src/jquery.contextMenu.js

@@ -1428,7 +1428,7 @@
                                 break;
 
                             case 'select':
-                                item.$input.val(item.selected || '');
+                                item.$input.val((item.selected === 0 ? "0" : item.selected) || '');
                                 break;
                         }
                     }