MFC: userid must be set in new grade too

grade/report/grader/lib.php

@@ -357,6 +357,7 @@ function load_final_grades() {
                 if (!isset($this->grades[$userid][$itemid])) {
                     $this->grades[$userid][$itemid] = new grade_grade();
                     $this->grades[$userid][$itemid]->itemid = $itemid;
+                    $this->grades[$userid][$itemid]->userid = $userid;
                     $this->grades[$userid][$itemid]->grade_item =& $this->gtree->items[$itemid]; // db caching
                 }
             }