Fix test impredictability

Alvaro Herrera <alvherre@alvh.no-ip.org>

Commit: 186b6df2e62251e5e1f3cae8a3257c7226f4188c
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: 2018-03-26T14:46:04Z
Releases: 11.0
Fix test impredictability

Test 'triggers' fails when another one creates triggers concurrently at
some precise time, because of a missing WHERE clause.

Per buildfarm members snapper, desmoxytes.

Files