Remove Ion Rifle from Cargo List

[ben10083]

As title says, remove the Ion Rifle from the cargo order list. I feel that the ion rifle should not be accessable to crew without RnD or other stuff like that, as a ion rifle can shut down many antags, and a entire species.

 The PEAC fits the role of the ion well, and I feel that having the ion rifle being orderable from cargo was a oversight when it was being replaced.

[MattAtlas]

Don't really see why, considering that security can order many other types of game-ending gear from cargo, such as bullpups and the laser sniper rifle, which are both absolutely ridiculous guns. Ions are on the same powerlevel, except much more niche.