`get_socket_inodes()` calls `os.listdir()` and then iterates on the
results using `os.readlink()`. However a file may disappear from the
directory after `os.listdir()` and before `os.readlink()` resulting in a
`FileNotFoundError` exception.
It is expected that this may happen for `bitcoind` which is running and
could open or close files or sockets at any time. Thus ignore the
`FileNotFoundError` exception.