server: Various offboard fixes

Peterrequested to merge
bugfix/server-offboard-fixes into master

  • check or remove this line after you've added a CHANGELOG entry or if your PR doesn't need one (they should go into CHANGELOG/unreleased/)

  • Expire pending offboards on the server side, we missed this and it could've led to UTXO lockup until the next restart

  • Make prepare_offboard idempotent when given the exact same request again

Edited by Peter

Merge request reports