Fixes being able to put items back in the specialist case (#6897)

# About the pull request
Closes #6896 
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# Explain why it's good for the game
Fixes a bug
# Testing Photographs and Procedure
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# Changelog
:cl:
fix: You can no longer put items back in the specialist case after
taking them out
/:cl:

code/modules/cm_marines/equipment/kit_boxes.dm

@@ -9,6 +9,7 @@
 	storage_slots = 14
 	slowdown = 1
 	can_hold = list() //Nada. Once you take the stuff out it doesn't fit back in.
+	max_w_class = 0
 	foldable = null
 
 /obj/item/storage/box/spec/update_icon()