Revert "[MIRROR] Replace all secondary flags with bitflags stored in the flags_2 var" (#2457)

ok you know what yeah i think i'll properly mirror https://github.com/Citadel-Station-13/Citadel-Station-13/pull/2411

code/game/objects/structures/aliens.dm

@@ -42,7 +42,7 @@
 	icon_state = "gelmound"
 
 /obj/structure/alien/gelpod/deconstruct(disassembled = TRUE)
-	if(!(flags_1 & NODECONSTRUCT_1))
+	if(!(flags & NODECONSTRUCT))
 		new/obj/effect/mob_spawn/human/corpse/damaged(get_turf(src))
 	qdel(src)
 
@@ -297,7 +297,7 @@
 						break
 
 /obj/structure/alien/egg/obj_break(damage_flag)
-	if(!(flags_1 & NODECONSTRUCT_1))
+	if(!(flags & NODECONSTRUCT))
 		if(status != BURST)
 			Burst(kill=TRUE)