Adds missing pistol magazines to the Atlas. (#3864)

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## About The Pull Request

Adds 4 CM-23 magazines to the Atlas's armory, as before there were 0.
Honestly they feel like too few, but, i'm keeping consistant with the
rest of the ship.

## Why It's Good For The Game

Before, outside of the officer's guncases, there were no magazines for
CM-23's, making them COMPLETELY unusable.
## Changelog

:cl:
add: Added 4 CM-23 magazines to the Atlas's armory. You can now use the
CM-23s stored there.
/:cl:

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_maps/shuttles/minutemen/minutemen_atlas.dmm

@@ -4576,6 +4576,10 @@
 	pixel_x = 11;
 	pixel_y = -8
 	},
+/obj/item/ammo_box/magazine/cm23,
+/obj/item/ammo_box/magazine/cm23,
+/obj/item/ammo_box/magazine/cm23,
+/obj/item/ammo_box/magazine/cm23,
 /turf/open/floor/plasteel/dark,
 /area/ship/security)
 "Vw" = (