Currently, an empty folder is created when extracting an archive over
Nautilus which contains one file with the same name as the archive.
This is because gnome-autoar always creates the top-level folder, but
the one file archive with the same name should be extracted directly
without creating additional folders. Otherwise the `conflict` signal
is emitted and Nautilus by default skips conflicting files, so only
empty folder remains after extraction. This problem have not been
unfortunately noticed by the `test-one-file-same-name` unit test due to
differences in the `decide-destination` signal handling. Let's do not
create the top-level folder at all as `g_file_make_directory_with_parents`
is used later anyway.

Fixes: #28