Update init.js

Author: alexgreat70

app/assets/javascripts/active_admin/searchable_select/init.js

@@ -8,7 +8,7 @@
       var options = $.extend(extra || {}, item.data('searchableSelect'));
 
       // default option allow clear
-      if (options.allowClear != undefined)
+      if (options.allowClear == undefined)
         options.allowClear = true;
 
       var url = item.data('ajaxUrl');