stack/logrotate: fix copytruncate being accidentally always enabled

In 0409f691 (zope4: Handle log rotation following Zope documentation.,
2022-03-10) we added an option to use copytruncate in logrotate, with
a default value of "false" which is true in jinja2, so it was actually
enabled every where.

This change brings the expected behavior copytruncate option in
logrotate stack, it is not enabled by default, unless explicitly using
copytruncate = true