ffap-url-unwrap-local

ffap-url-unwrap-local is a variable defined in `ffap.el'.
Its value is

t

Documentation:
If non-nil, convert some URLs to local file names before prompting.
Only "file:" and "ftp:" URLs are converted, and only if they
do not specify a host, or the host is either "localhost" or
equal to `system-name'.

You can customize this variable.