r1soft public key is not available

When updating a server with r1soft backup manager installed, i get following error

root@localhost:~# apt update
Hit:1 http://mirrors.linode.com/ubuntu xenial InRelease
Hit:2 http://mirrors.linode.com/ubuntu xenial-updates InRelease
Hit:3 http://mirrors.linode.com/ubuntu xenial-backports InRelease
Ign:4 http://repo.r1soft.com/apt stable InRelease
Hit:6 http://security.ubuntu.com/ubuntu xenial-security InRelease
Get:5 http://repo.r1soft.com/apt stable Release [3,255 B]
Get:7 http://repo.r1soft.com/apt stable Release.gpg [230 B]
Err:7 http://repo.r1soft.com/apt stable Release.gpg
The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 39A4965166BD1D82
Fetched 3,485 B in 0s (11.0 kB/s)
Reading package lists… Done
Building dependency tree
Reading state information… Done
All packages are up to date.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://repo.r1soft.com/apt stable Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 39A4965166BD1D82
W: Failed to fetch http://repo.r1soft.com/apt/dists/stable/Release.gpg The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 39A4965166BD1D82
W: Some index files failed to download. They have been ignored, or old ones used instead.
root@localhost:~#

This is because r1soft changed the key they used before. To fix, run

Now apt update will work properly.

r1soft