gently flapping tdb test

[Douglas Bagnall]

This one has happened four times since 2018-04-17.

That's a faint enough signal to get lost, but enough to suggest tdb
stopped agreeing with its tests early this year.

On 29/11/18 12:11 PM, autobuild wrote:
>    https://git.samba.org/autobuild.flakey.sn-devel-144/2018-11-29-0011/tdb.stderr
>    https://git.samba.org/autobuild.flakey.sn-devel-144/2018-11-29-0011/tdb.stdout

> ...tdb1-run-marklock-deadlock
> ...tdb1-run-allrecord-traverse-deadlock
> tdb1-run-allrecord-traverse-deadlock failed:
> ........................marklock-deadlock-fcntl.tdb tests done
> .................do_allrecord_lock: traverse should fail
> ......ret should succeed
> .Running Python test with /usr/bin/python: python/tests/simple.py
> python testsuite returned 0
> 

Douglas