change update order, update-vt-info run as gvm

[itiligent]

https://greenbone.github.io/docs/latest/21.04/source-build/index.html#performing-an-initial-feed-synchronization says the feed should be updated in a specific order ie sudo -u gvm greenbone-nvt-sync sudo -u gvm greenbone-feed-sync --type SCAP sudo -u gvm greenbone-feed-sync --type CERT sudo -u gvm greenbone-feed-sync --type GVMD_DATA Changes the script to reflect this

[yu210148]

Thanks for this 🙂