avoid excessive TCP reconnections in some cases

See commit messages and ./NEWS for details.

requested review from @vcunat

assigned to @amrazek

added 5 commits

• 627a3f49...8b018aa7 - 2 commits from branch master
• a9528e33 - daemon/worker: call server_selection.error() more
• 3e28a8a6 - daemon/io: penalize servers that close without reply
• 6baf7664 - NEWS for the past two commits

Compare with previous version

approved this merge request

merged

mentioned in commit 7d704bbb

For reference, the reporters got CVE-2023-26249 identifier for this.