agent: Fix sock_inotify_fd handling.
* agent/gpg-agent.c (handle_connections): Also check SOCK_INOTIFY_FD when spawning check_onw_socket_thread. When removal of the socket is detected, do same as AGENT_PROBLEM_SOCKET_TAKEOVER.
- GnuPG-bug-id: T6692
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>