FIX fileupload.js error message

src/ext/js/fileupload.js

@@ -118,8 +118,8 @@ var fileupload = new function() {
         var input = $(property).find(".caosdb-f-property-value input");
         return function(event, error, xhr) {
             if (xhr.status == "401") {
-                // add success message
-                input.after(`<div class="alert alert-success alert-dismissible"
+                // add error message
+                input.after(`<div class="alert alert-danger alert-dismissible"
     role="alert">
     <button type="button" class="close" data-dismiss="alert"
         aria-label="Close"><span aria-hidden="true">&times;</span></button>