socks5: Implement timeout to detect bogus service.
* src/assuan-socket.c (TIMEOUT_NOT_WAITING_SOCKS5_FOREVER): New. (socks5_connect): Call 'select' in order to not waiting response forever.
- GnuPG-bug-id: T3381
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>