When I try to install with apt on Ubuntu it fails.
sudo apt-get update gives

@ https://deb.packager.io/gh/opf/openproject-ce/dists/xenial/Release.gpg: Signature by key 6257DF9972462F57A20FFB2AB6D583CCBD33EEB8 uses weak digest algorithm (SHA1)@

I don’t want to install manually. Is there a way to fix that?