patches/knot: update to version 2.9.1
This PR updates knot in packages feed to version 2.9.1 It should be merged with sync with https://gitlab.labs.nic.cz/turris/turris-os-packages/merge_requests/157 which removes the knot from turris-os-packages master.
The idea behind this is, that we will use upstream packages version which should save us the maintenance of knot package.