Adds a crew transfer notice for new players

Adds the "The station is currently undergoing evacuation procedures"
notice for new people trying to join when there's a crew transfer going
on.

code/controllers/shuttle_controller.dm

@@ -67,6 +67,7 @@ datum/shuttle_controller
 				captain_announce("The shuttle has been recalled.")
 				setdirection(-1)
 				online = 1
+				alert = 0 // set alert back to 0 after an admin recall
 				return
 
 	// returns the time (in seconds) before shuttle arrival