Revert "remove leftover code"

This reverts commit 24fc61fedf.

files/helpers/cron.py

@@ -47,6 +47,9 @@ def cron_fn(every_5m, every_1d, every_1mo):
 				_award_timers_task()
 				g.db.commit()
 
+				_unpin_expired()
+				g.db.commit()
+
 				_grant_one_year_badges()
 				g.db.commit()
 
@@ -313,6 +316,22 @@ def _award_timers_task():
 	})
 	_process_timer(User.flairchanged, [96], "Your temporary flair-lock has expired. You can now change your flair!")
 
+
+def _unpin_expired():
+	t = int(time.time())
+	pins = []
+
+	for cls in (Post, Comment):
+		pins += g.db.query(cls).options(load_only(cls.id)).filter(cls.stickied_utc < t)
+
+	for pin in pins:
+		pin.stickied = None
+		pin.stickied_utc = None
+		g.db.add(pin)
+
+	if pins:
+		cache.delete_memoized(frontlist)
+
 def _give_marseybux_salary():
 	for u in g.db.query(User).filter(User.admin_level > 0).all():
 		marseybux_salary = u.admin_level * 10000