[pve-devel] [RFC qemu-server] apt hook: warn against using 'upgrade' command

[Dominik Csapak]

just to mention it (i think it's not widely known):

'apt upgrade' behaves slightly different than 'apt-get upgrade'

while the former also installs new packages if necessary, the latter
doesn't, so an 'apt upgrade' will maybe work ok in most sitations.
I guess we want to filter it out nonetheless?

(none of the commands above will remove packages)