Stops shuttles from bringing background turfs with them. (#15580)

code/modules/power/cable.dm

@@ -29,6 +29,7 @@ By design, d1 is the smallest direction and d2 is the highest
 	desc = "A flexible superconducting cable for heavy-duty power transfer."
 	icon = 'icons/obj/power_cond_white.dmi'
 	icon_state = "0-1"
+	obj_flags = OBJ_FLAG_MOVES_UNSUPPORTED
 	var/d1 = 0
 	var/d2 = 1
 	layer = CABLE_LAYER //Just below unary stuff, which is at 2.45 and above pipes, which are at 2.4