libs: update to nfs4j-0.8.1

Changelog for nfs4j-0.8.0..nfs4j-0.8.1
    * [a041674] nfsv41: client: do not send getattr to DS
    * [2b6703e] test: suppress deprecation warning
    * [3a33b4c] acl: fix permission check on listdirectory
    * [e6f0783] mount: add support for symlinks

Ticket: #8410
Acked-by: Paul Millar
Target: master, 2.10, 2.9, 2.8, 2.7, 2.6
Require-book: no
Require-notes: yes
(cherry picked from commit 95a193a4708d25e05d9c601629af39f3bd61f356)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Merge pull request #790 from kofemann/nfs4j-0.8.1-2.9

libs: update to nfs4j-0.8.1