Bugfix for the automake ("global options already processed") error

The bug is due to Scribe calling AM_INIT_AUTOMAKE in both the top of configure.ac and inside FB_INITIALIZE defined in acinclude.m4. The solution is to comment the AM_INIT_AUTOMAKE.

Ref: https://www.bountysource.com/issues/646383-install-on-osx-with-thrift-0-5-0