MDL-64531 course: course_delete_module shouldn't output during AJAX

Committer's note: This change was originally part of a bigger patchset
submitted by the author. This is a stripped-down version that does not
use phpunit tests for the new behaviour.

course/lib.php

@@ -1151,7 +1151,9 @@ function course_delete_module($cmid, $async = false) {
     }
 
     // Delete activity context questions and question categories.
-    question_delete_activity($cm);
+    $showinfo = !defined('AJAX_SCRIPT') || AJAX_SCRIPT == '0';
+
+    question_delete_activity($cm, $showinfo);
 
     // Call the delete_instance function, if it returns false throw an exception.
     if (!$deleteinstancefunction($cm->instance)) {