[Map Update] pl_barnblitz_pro8

According to nominate list, currently running pl_barnblitz_pro7
https://tf2maps.net/downloads/barnblitz.1068/

Changes from previous version
-reverted first red forward spawn

 

I wanna say we tried pro8 and had issues, but I'm not sure.
Updated to pro8 either way.

 

Reverted back to version 7, version 8 does have problems. Cart drops at the end of map but doesnt end the round.