nfs: fall back to numeric mapping by default

Linux client uses number based mapping by default.
This makes dCache default configuration to have
'bad' behaviour. Let make our default same as linux
has.

Acked-by: Paul Millar
Target: master, 2.6
Require-book: no
Require-notes: yes
libs: use bugfix release of jpnfs

chagelog:
  * [adfcb19] nfs: fix readdir caching

Ticket: #7978
Acked-by: Paul Millar
Target: master, 2.6
Require-book: no
Require-notes: yes