configure.ac: Do not enable -Wl,--no-undefined on Mac OS X.

This patch fixes this build error on Mac OS X.

  CCLD     libglapi.la
clang: warning: argument unused during compilation: '-pthread'
clang: warning: argument unused during compilation: '-pthread'
ld: unknown option: --no-undefined
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
1 file changed