Makes the station Z level into a list instead of a single define

code/datums/mind.dm

@@ -535,7 +535,7 @@
 				if(I == src)
 					continue
 				var/mob/M = I
-				if(M.z == ZLEVEL_STATION && !M.stat)
+				if((M.z in GLOB.station_z_levels) && !M.stat)
 					last_healthy_headrev = FALSE
 					break
 			text += "head | not mindshielded | <a href='?src=\ref[src];revolution=clear'>employee</a> | <b>[last_healthy_headrev ? "<font color='red'>LAST </font> " : ""]HEADREV</b> | <a href='?src=\ref[src];revolution=rev'>rev</a>"