gio: Fix completion of URIs without hostname part
gio: Fix completion of URIs without hostname part

Currently, "gio list file:///h<tab>" doesn't complete "file:///home"
because the result of "dirname file:///h" is not "file:///" but "file:/",
which breaks the consequent logic. Let's subtract basename from the
path in order to workaround this issue.

endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib