Limits Powersinks + Crab-17 purchases to once each per traitor per round. (#1219)

## About The Pull Request

Limits Powersinks and Crab-17 purchases to once each per traitor per
round.

## Why It's Good For The Game

Powersink and Crab spam is pretty awful. A lot of people recently have
been spamming these two objectives and then doing nothing of substance
with them. Traitors should be using their TC to further the round and
create meaningful conflict instead of what can basically be described as
being in a constant state of soft grief.

## Proof Of Testing

If it compiles, it werks.

## Changelog

🆑 BurgerBB
del: Limits Powersinks + Crab-17 purchases to once each per traitor per
round.
/🆑

Co-authored-by: Waterpig <49160555+Majkl-J@users.noreply.github.com>

modular_zubbers/code/modules/uplink/uplink_items/device_tools.dm

@@ -1,3 +1,7 @@
 /datum/uplink_item/device_tools/suspiciousphone
 	surplus = 0
 	cant_discount = TRUE
+	limited_stock = 1
+
+/datum/uplink_item/device_tools/powersink
+	limited_stock = 1