Base class's 'Qt5FilePicker::setTitle' is the same.

Change-Id: I071bf5f962c2d8b0821d78e97793c8637f5c0a1b
Reviewed-on: https://gerrit.libreoffice.org/68044
Tested-by: Jenkins
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>
(cherry picked from commit 4a5761b6)
Reviewed-on: https://gerrit.libreoffice.org/72641