add back nfs and nfs4 file systems

Fix gentoo bug #427996 correctly.
We should attempt to mount the file systems, but not try to start the
daemons. The previous fix removed mounting the file systems as well as
starting the daemons.

X-Gentoo-Bug: 508574
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=508574