Error: The repository '...' is no longer signed

[Diego Vadell <diego.m.vadell@xxxxxxxxx>]

Hi,

    I wanted to update trinity today (Ubuntu 18.04) and got this message:

Err:7 http://mirror.xcer.cz/trinity-sb bionic InRelease
  403  Forbidden [IP: 91.241.23.210 80]
Hit:8 https://packages.cisofy.com/community/lynis/deb stable InRelease
Reading package lists... Done
E: Failed to fetch http://mirror.xcer.cz/trinity-sb/dists/bionic/InRelease  403  Forbidden [IP: 91.241.23.210 80]
E: The repository 'http://mirror.xcer.cz/trinity-sb bionic InRelease' is no longer signed.

I went to the wiki (Preliminary Stable Builds) and rerun the GPG key import, but it looks like I already had it:

  sudo apt-key adv --keyserver pool.sks-keyservers.net --recv-key A04BE668
Executing: /tmp/apt-key-gpghome.fCUStJLtMA/gpg.1.sh --keyserver pool.sks-keyservers.net --recv-key A04BE668
gpg: key 608F5293A04BE668: 7 signatures not checked due to missing keys
gpg: key 608F5293A04BE668: "Slávek Banko <slavek.banko@xxxxxxx>" not changed
gpg: Total number processed: 1
gpg:              unchanged: 1

Is everybody able to update?

Thanks in advance,

 -- Diego.