Convert some bools to TRUE/FALSE instead of 1/0. (#11100)

Co-authored-by: Aronai Sieyes <arokha@arokha.com>

code/modules/overmap/overmap_shuttle.dm

@@ -126,8 +126,8 @@
 	desc = "The fuel input port of the shuttle. Holds one fuel tank. Use a crowbar to open and close it."
 	icon = 'icons/turf/shuttle_parts.dmi'
 	icon_state = "fuel_port"
-	density = 0
-	anchored = 1
+	density = FALSE
+	anchored = TRUE
 	var/icon_closed = "fuel_port"
 	var/icon_empty = "fuel_port_empty"
 	var/icon_full = "fuel_port_full"