fix missing ; in event

classes/event/gradeimporter_submission_created.php

@@ -18,7 +18,7 @@ class gradeimporter_submission_created extends \core\event\base {
     */ 
     public function get_description(){
         return "The user with id '$this->userid' has created a submission " . 
-                "on the grade importer with the course module id '$this->contextinstanceid'."  
+                "on the grade importer with the course module id '$this->contextinstanceid'." ; 
     }
 
     /**