depends: force a new host id string if FORCE_USE_SYSTEM_CLANG is in use
depends: force a new host id string if FORCE_USE_SYSTEM_CLANG is in use

This should be caught by the differing clang --version outputs, but because we
haven't yet extracted our pinned clang, the system one is actually used for the
version check. That's not a problem because bumping our pinned clang will
cause a rebuild of everything anyway.

PIVX-Project/PIVX,PIVX-Project/PIVX,Darknet-Crypto/Darknet,PIVX-Project/PIVX,Darknet-Crypto/Darknet,PIVX-Project/PIVX,Darknet-Crypto/Darknet,PIVX-Project/PIVX,PIVX-Project/PIVX,PIVX-Project/PIVX,PIVX-Project/PIVX,PIVX-Project/PIVX,Darknet-Crypto/Darknet,Darknet-Crypto/Darknet,Darknet-Crypto/Darknet