FUSE on OpenBSD

Concerning #1696:

OpenBSD offers in kernel support for FUSE 2.6. Borg relies on llfuse,
which relies on FUSE >2.9.

I'm not aware of plans to bring FUSE on OpenBSD to a more recent
version.

Signed-off-by: Björn Ketelaars <bjorn.ketelaars@hydroxide.nl>

Vagrantfile

@@ -114,7 +114,6 @@ def packages_openbsd
     chsh -s /usr/local/bin/bash vagrant
     pkg_add openssl
     pkg_add lz4
-    # pkg_add fuse  # does not install, sdl dependency missing
     pkg_add git  # no fakeroot
     pkg_add py3-setuptools
     ln -sf /usr/local/bin/python3.4 /usr/local/bin/python3