www/mod_pagespeed: Fix build with OpenSSL-base w/o gperf in base
This patch edits select_openssl.gyp for fixing the selection of -L -I flags for build.
Also adds compatibilty flags for the functions that openssl of base doesn't provide.

Reviewed by: mat
Sponsored by: Netzkommune GmbH
Differential Revision: https://reviews.freebsd.org/D13316