So the mistake I did in commit 457acbfa
(UITest_writer_tests: split this into 4 parts, 2018-07-03) does not
happen again.

Change-Id: Ia28ed1fe9909d9c46ebe95d3a1926b0dced46140
Reviewed-on: https://gerrit.libreoffice.org/66180Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>