The value 100000 already was in the year 2000 initial commit,
probably some memory and performance constraints back then. At
least one full column should be sortable, make it two so we don't
bail out that early for functions like MODE() that can take
multiple ranges. In fact maybe ScMatrix::IsSizeAllocatable()
should be taken into account, which is much larger though and
QuickSort() might not play well with it.

Change-Id: I061abfd0f061c8df62c31468df744eb5dc7152be
Reviewed-on: https://gerrit.libreoffice.org/59637Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>