Fix for salvagers not collecting money for Indy

Salvage trucks were not able to collect money from indy/green vehicle
wrecks. The fix was just to add `resistance` to the allowed sides that a
salvager can collect from.

I've tested this fix on local server, and I've seen it collect money
from indy wrecks.
Merge pull request #88 from DanielVF/master

Fix for salvagers not collecting money for Indy