Log Message:
Substitute path to openssl more thoroughly

This package can depend on builtin openssl or pkgsrc openssl.
However, it had paths from the base system hardcoded.  Be more
thorough about using builtin vs pkgsrc paths.  This is a minimal
change to use builtin/pkgsrc paths; future commits will note latent
issues uncovered in the process.

Based on a report to pkgsrc-users by J. Lewis Muir.