Two minor sunskipper tweaks. (#3204)

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## About The Pull Request
- Changed it's prefix to SV
- adds a missing pipe
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it is
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## Changelog

:cl:
tweak: Changed sunskipper's prefix to SV.
fix: Added a missing pipe to the sunskipper.
/:cl:

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_maps/configs/independent_sunskipper.json

@@ -1,7 +1,7 @@
 {
 	"$schema": "https://raw.githubusercontent.com/shiptest-ss13/Shiptest/master/_maps/ship_config_schema.json",
 	"map_name": "Sunskipper-class Culinary Vessel",
-	"prefix": "ISV",
+	"prefix": "SV",
 	"namelists": ["CRUISE", "NATURAL"],
 	"map_short_name": "Sunskipper-class",
 	"map_path": "_maps/shuttles/independent/independent_sunskipper.dmm",

_maps/shuttles/independent/independent_sunskipper.dmm

@@ -1560,6 +1560,9 @@
 /obj/structure/cable/green{
 	icon_state = "4-9"
 	},
+/obj/machinery/atmospherics/pipe/simple/scrubbers/hidden/layer4{
+	dir = 8
+	},
 /turf/open/floor/carpet/nanoweave,
 /area/ship/crew/cryo)
 "tP" = (