MDL-47930 mod_forum: Detect subscription to subscription disabled forums

Return forums with disabled subscription that you are subscribed to in
forum_get_subscribed forums

mod/forum/lib.php

@@ -4800,7 +4800,6 @@ function forum_get_subscribed_forums($course) {
               FROM {forum} f
                    LEFT JOIN {forum_subscriptions} fs ON (fs.forum = f.id AND fs.userid = ?)
              WHERE f.course = ?
-                   AND f.forcesubscribe <> ".FORUM_DISALLOWSUBSCRIBE."
                    AND (f.forcesubscribe = ".FORUM_FORCESUBSCRIBE." OR fs.id IS NOT NULL)";
     if ($subscribed = $DB->get_records_sql($sql, array($USER->id, $course->id))) {
         foreach ($subscribed as $s) {