Remove the option for enabling flock-locks. flock-locks don't exist anymore
in 1.6.x. As well, tcp_wrappers doesn't exist as a port anymore. Remove
it from the optional LIB_DEPENDS.
Also, note, 1.6.0 enables the CNID DID calculation and persistence
scheme by _default_. To revert to the old DID method, specify
WITHOUT_CNID when building the port. More info is available in the Makefile