configure.ac: fix test == bashism
configure.ac: fix test == bashism

Signed-off-by: Austin Seipp <7ea35d812706d9213868749011af1ed4fa2f6aa0@well-typed.com>

hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay