fusefrontend: ensure directories without W or X perms can be deleted
fusefrontend: ensure directories without W or X perms can be deleted

This fixed the "Permission denied" bug, but still has the problem that
the directory may be replaced behind our back. Mitigated by the fact
that we skip the workaround when running as root with -allow_other.

https://github.com/rfjakob/gocryptfs/issues/354

rfjakob/gocryptfs,rfjakob/gocryptfs,rfjakob/gocryptfs,rfjakob/gocryptfs