Updates flags

Changed to reflect this code from the main SC:

if FreeBSD:
    env.Append(CPPFLAGS = ['-DMDB_DSYNC=O_SYNC'])

if OSX:
    env.Append(LINKFLAGS = ['-L/usr/local/opt/openssl/lib'])
    env.Append(CXXFLAGS = ['-I/usr/local/opt/openssl/include'])