Add uint64 to generated legacy nng_setopt_* functions.
Add uint64 to generated legacy nng_setopt_* functions.

The functions nng_dialer_setopt_uint64 and nng_dialer_setopt_uint64 are
declared in nng.h but not defined, causing errors at runtime of programs
that expect them to be defined.

nanomsg/nng,nanomsg/nng,nanomsg/nng,nanomsg/nng