Due to previously intruduced optimizations, it is safe and fast enough
to navigate through a 500k rows speadsheet.

Change-Id: I865d0b60629b5bbf796e9e48df6ff21242a13e5a
Reviewed-on: https://gerrit.libreoffice.org/40454Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Marco Cecchetti <mrcekets@gmail.com>