Do not drop CFLAGS from c_glib compilation

CFLAGS contains important flags. Dropping it introduces e.g. such issues:
https://sourceware.org/bugzilla/show_bug.cgi?id=13979

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>

This closes #284
THRIFT-2846 Expose ciphers parameter from ssl.wrap_socket()

Patch: Rodney Richardson

This closes #277