Third party source added to board manager but cant find attiny core library anymore

[lupusworax]

seems to be a very recent problem.
Worked flawless just a few days ago, now the attinycore library seems to be gone.
adding the source seems like normal:

but when I search for attinycore in library manger nothing comes up:

[mikedevnull]

I also stumbled upon this.
I think the problem is that that the SSL certificate for https://drazzy.com/ expired on February 12th. (It automatically redirects from http://drazzy.com to https://drazzy.com)

[hmeijdam]

There is a workaround