The message expiringblock was removed from core in 2013: https://gerrit.wikimedia.org/r/c/mediawiki/core/+/22433
However, it is still used in the GlobalBlocking extension, and has many translations.
It would be nice to move it cleanly from the core code to the extension code, and perhaps the message key should be changed, too.
Change 682278 had a related patch set uploaded (by Amire80; author: Amire80):
[mediawiki/core@master] Remove the message expiringblock
Change 682799 had a related patch set uploaded (by Amire80; author: Amire80):
[mediawiki/extensions/GlobalBlocking@master] Add local copies of expiringblock and infiniteblock
Change 682278 merged by jenkins-bot:
[mediawiki/core@master] Remove the message expiringblock
Change 682799 merged by jenkins-bot:
[mediawiki/extensions/GlobalBlocking@master] Add local copies of expiringblock and infiniteblock