Disassembling Light Tiles yield more cable than used in construction

[LordMyroc]

Description of issue

Disassembling a Light (Floor) Tile yields you five pieces of cable coil, when only two are used in construction.

Difference between expected and actual behavior

Expected to receive the same amount of cable back, instead found a way to produce infinite cables.

Steps to reproduce

1. Apply cable to glass
2. Apply wirecutter to the wired glass
3. +3 cable coil

Length of time in which bug has been known to occur

Just discovered this

Server revision

2b6aa7b06aecca4a51cfa4b800cb771f35d625e9

Issue bingo

• [x] Issue could be reproduced at least once
• [ ] Issue could be reproduced by different players
• [ ] Issue could be reproduced in multiple rounds
• [x] Issue happened in a recent (less than 7 days ago) round
• [x] Couldn't find an existing issue about this

[Pathid]

Really simple to fix. The salvage amount wasn't adjusted when the cost was reduced. I'll do that right now. https://github.com/vgstation-coders/vgstation13/blob/5d73070f77f123bec728c93b414a21a0d7c40f5d/code/game/objects/items/stacks/sheets/light.dm#L19