New function ntbtls_get_hostname.
* src/ntbtls.h.in (ntbtls_get_hostname): New. * src/protocol.c (_ntbtls_get_hostname): New. * src/visibility.c, src/visibility.h: Export ntbtls_get_hostname. * src/libntbtls.def, src/libntbtls.vers: Ditto.
- Signed-off-by: Werner Koch <wk@gnupg.org>