Offer only course context roles for selection

classes/form/evaluserexport.php

@@ -39,7 +39,7 @@ class evaluserexport extends moodleform {
 
         $courseid = $this->_customdata['courseid'];
         $coursecontext = $this->_customdata['coursecontext'];
-        $viewableroles = get_profile_roles($coursecontext);
+        $viewableroles = get_roles_used_in_context($coursecontext, false);
         $roles = role_fix_names($viewableroles, $coursecontext, ROLENAME_ALIAS);
         $options = [];
         foreach ($roles as $role) {