Can't find best loot with metal detector without lucky trait.

[ArahnaBytes]

Describe the bug
If you don't have trait "Lucky", you can't find best tier loot with metal detector (steel spear, spiked mace and conan sword) even with 10 level in scavenging.

In function hcmetalsearch there are two errors.
if luck >= 30 then fails because luck = ZombRand(20) + skill is 29 at max without lucky trait. And if luck >= 5 then fails because luck = ZombRand(5) is from 0 to 4.