Steps to reproduce:

• Create news account for news.mozilla.giganews.com
• Subscribe to mozilla.test
• Try to "Copy Message Location" for some message in the newsgroup
• In the account preferences change host name to news.mozilla.org
• Try to "Copy Message Location" for some message in the newsgroup

Actual results:

After the change of the server news://news.mozilla.giganews.com/... URIs are still copied

Expected results:

news://news.mozilla.org/... URIs for actual host name.

A several years old real life case: switch from news.gmane.org to news.gmane.io. Thunderbird-101 have its own additional problems, In thunderbird-91 and earlier versions such operation is painful due to lost of message states (one case in the description of the seasoned Bug #548966)