ctdb-eventscripts: Switch on dumping of stuck nfsd threads

ctdb-eventscripts: Switch on dumping of stuck nfsd threads

This feature was added quite a while ago but was not enabled by
default.  It is a useful feature so enable it to dump stack traces of
up to 5 stuck processes by default.

This can be disabled by setting:

  CTDB_NFS_DUMP_STUCK_THREADS=0

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>
Autobuild-User(master): Amitay Isaacs <amitay@samba.org>
Autobuild-Date(master): Tue Feb 25 04:06:45 CET 2014 on sn-devel-104