...and add missed variable inititialization in options uitest that
causes Jenkins to report test failure when testing patches concerning
options charts default colors page.

Change-Id: I324bcbb7834abf1a270bfce01eb84db280420409
Reviewed-on: https://gerrit.libreoffice.org/67236
Tested-by: Jenkins
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>