When importing CSV with multiple lines in a cell, it looks as if some content
was lost.  It is not, it is in the spreadsheet, but looks very confusing, and
only way to get around that was to let the heights be recalculated.

It seems that the large CSV still opens in reasonable time even with this
change in.

Change-Id: I701110fcd8a92daa5f374d80f5af696666a7aa6a
Reviewed-on: https://gerrit.libreoffice.org/10499Tested-by: Eike Rathke <erack@redhat.com>
Reviewed-by: Eike Rathke <erack@redhat.com>