Sometimes, the flaky test `MessageCacheTest::testLoadFromDB_fetchLatestRevision` blocks merge, see: https://integration.wikimedia.org/ci/job/mediawiki-quibble-vendor-postgres-php70-docker/2636/console
```
00:09:16 1) MessageCacheTest::testLoadFromDB_fetchLatestRevision
00:09:16 === Logs generated by test case
00:09:16 [caches] [info] parser: HashBagOStuff {"private":false}
00:09:16 [StashEdit] [debug] Empty cache for key 'postgres-mediawiki-unittest_:stashed-edit-info:8db213b807f4e71df8c09cd5017c785b:5d9ed11feeb6ebe90f34bd8a5086ab44206045d0:90f42dc8c99187877261a42fd0a194b3' ('MediaWiki:Log'); user '127.0.0.1'. []
00:09:16 [MessageCache] [info] MessageCache::load: Loading de... local cache is empty, global cache is empty, loading from database {"private":false}
00:09:16 [MessageCache] [info] MessageCache::load: Loading en... local cache is empty, global cache is empty, loading from database {"private":false}
00:09:16 [wfDebug] [debug] IP: 127.0.0.1 {"private":false}
....
00:09:16 Failed asserting that two strings are identical.
00:09:16 --- Expected
00:09:16 +++ Actual
00:09:16 @@ @@
00:09:16 -' Test drei'
00:09:16 +' IMPORTED OLD TEST'
00:09:16
00:09:16 /workspace/src/tests/phpunit/includes/cache/MessageCacheTest.php:258
00:09:16 /workspace/src/tests/phpunit/MediaWikiTestCase.php:425
00:09:16 /workspace/src/maintenance/doMaintenance.php:94
00:09:16
00:09:16 FAILURES!
00:09:16 Tests: 7863, Assertions: 60892, Failures: 1, Skipped: 118.
```
Patches affected;
* https://gerrit.wikimedia.org/r/c/mediawiki/core/+/498497
*