Always link to bundled hiredis
Always link to bundled hiredis

Ruby's mkmf cannot be configured to use a local, static library instead
of a global dynamic one. It tried to link against a version that was
already installed in /usr/lib or similar, which broke when hiredis was
upgraded to 0.10 (a few function symbols changed). This change makes
sure the extension is always linked against the bundled, static version.

ferdinandrosario/hiredis-rb,redis/hiredis-rb,dixiS/hiredis-rb,redis/hiredis-rb,loggator/hiredis-rb,loggator/hiredis-rb,ferdinandrosario/hiredis-rb,dixiS/hiredis-rb