update Cassandra debian repository url

docs/devel/developer-setup.rst

@@ -28,7 +28,7 @@ package manager. On Debian/Ubuntu-based distributions::
   sudo wget https://www.postgresql.org/media/keys/ACCC4CF8.asc -O /etc/apt/trusted.gpg.d/postgresql.asc
   echo "deb https://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" | sudo tee -a /etc/apt/sources.list.d/pgdg.list
   sudo wget https://downloads.apache.org/cassandra/KEYS -O /etc/apt/trusted.gpg.d/cassandra.asc
-  echo "deb https://downloads.apache.org/cassandra/debian 40x main" | sudo tee -a /etc/apt/sources.list.d/cassandra.list
+  echo "deb https://debian.cassandra.apache.org 41x main" | sudo tee -a /etc/apt/sources.list.d/cassandra.list
   sudo apt update
   sudo apt install \
       build-essential pkg-config lzip rsync \

docs/sysadm/deployment/howto-debian-packaging.rst

@@ -456,7 +456,7 @@ or if you need some third-party repository, say cassandra (for swh-storage):
    gbp buildpackage --git-builder=sbuild -As \
      --no-clean-source --force-orig-source \
      --extra-repository='deb [trusted=yes] https://debian.softwareheritage.org/ unstable main' \
-     --extra-repository='deb [arch=amd64 trusted=yes] https://downloads.apache.org/cassandra/debian/ 40x main'
+     --extra-repository='deb [arch=amd64 trusted=yes] https://debian.cassandra.apache.org 41x main'
 
 For **buster**, it would be (note the usage of aptitude as resolver as the
 backports repository is used):