Plone-site won't create instance

[Krzysztof Troska]

Binary package hint: plone-site

plone-site, can't make a instance after installation of plone-site package, after installation in command line there is a error:
dzhandle make-instance: service user must be specified as user:group

Fix:
there is a bug in postinstall scripts (maybe some other also) when there is like this:
[...]
        if dzhandle -z $ZVER make-instance -u "$user:$password" $INSTANCE \
            --addon-mode=manual --restart=end -t tree-linked \
            --service-port=$port --service-user=zope $ZEOSERVER
[...]

this will generate a error because parameters in option service-user should be something like this: --service-user=zope:zope. on 81 line in postinst.