databases/pgrouting: revert last commit

This reverts commit b7fb45fcb4cfb4a9e0edb7d4e67edb7f11e104f7.

This was already updated to 3.8.0 - applying the patch a second time puts it back to 3.7.3.

Reported by: Martin Birgmeier <d8zNeCFG@aon.at> and portmgr@