for the std::min we need the header <algorithm>

Change-Id: I83d815e1fe8a7221c0eade58df5af887d5a9795a
Reviewed-on: https://gerrit.libreoffice.org/15921Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins <ci@libreoffice.org>