Remove useless ensure_directory() call
Remove useless ensure_directory() call

Util::get_unattended_dir() calls ensure_directory, but this functions
uses a system directory (DATADIR/PACKAGE_TARNAME/unattended) so
it's unlikely that the user will have the permissions to create
directories in this directory.

https://bugzilla.gnome.org/show_bug.cgi?id=676658

vbenes/gnome-boxes,vbenes/gnome-boxes