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I'm using Ubuntu 16.04 LTS. I downloaded and installed Geogebra 5 as a deb package. Since then, whenever I do anything with apt, a message is displayed saying:
W: http://www.geogebra.net/linux/dists/stable/InRelease: Signature by key 98272894F6478AA4434B41D3C072A32983A736CF uses weak digest algorithm (SHA1)
I tried uninstalling Geogebra and purging its repository with ppa-purge (but this didn't work since I couldn't find the repository). There was no entry for Geogebra in my installed software list in GNOME (Ubuntu) Software even before I uninstalled.
How should I solve this? I am aware that this is a problem on Geogebra's server's end but since I don't need to use it anymore, I need a way to remove the repository. Thanks!