Gitian: fix check path and detached signatures dir name
Gitian: fix check path and detached signatures dir name

- previous setting checked for ion folder instead of pivx
- previous setting checked for ion detached signatures instead of

npccoin/npccoin,PIVX-Project/PIVX,PIVX-Project/PIVX,benzmuircroft/REWIRE.io,Mrs-X/Darknet,benzmuircroft/REWIRE.io,Mrs-X/PIVX,Darknet-Crypto/Darknet,PIVX-Project/PIVX,PIVX-Project/PIVX,PIVX-Project/PIVX,PIVX-Project/PIVX,Darknet-Crypto/Darknet,npccoin/npccoin,Mrs-X/PIVX,Mrs-X/Darknet,npccoin/npccoin,npccoin/npccoin,npccoin/npccoin,Mrs-X/Darknet,Darknet-Crypto/Darknet,Mrs-X/PIVX,Mrs-X/Darknet,PIVX-Project/PIVX,Mrs-X/PIVX,benzmuircroft/REWIRE.io,Mrs-X/Darknet,Mrs-X/PIVX,benzmuircroft/REWIRE.io,benzmuircroft/REWIRE.io,PIVX-Project/PIVX,Mrs-X/Darknet,Mrs-X/PIVX,benzmuircroft/REWIRE.io,Darknet-Crypto/Darknet,npccoin/npccoin,Darknet-Crypto/Darknet,PIVX-Project/PIVX,Darknet-Crypto/Darknet