Version 1.1 and below used an RPC check via the showmount command
to check available remote host mountpoints, which works great with
NFSv2 and NFSv3. This does NOT work with NFSv4, so if an RPC error is
detected, it now presumes that NFSv4 is being used and attempts the
mount anyway if the server exists. If mounting does not occur
(e.g. "backgrounding" due to a misconfiguration) it immediately
unmounts the mountpoint instead of leaving it in the "backgrounded"
state. No configuration changes are needed.