Now browse to http://${VHOST_HOSTNAME}/${VHOST_APPDIR}
to complete the install.

Note: User data are stored in ${VHOST_ROOT}/groupoffice-<VERSION>/userdata
Local data are stored in ${MY_INSTALLDIR}/local

When you are done with the installation,
rm -Rf ${MY_INSTALLDIR}/install/
or use an .htaccess file to secure the installation directory.