History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 51–53 on 4866be1c9040201c52d96db802d35b2b1ce7f50b13a8a2f65a1ed1f6f854c6bb. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 51,53:crates/hub/src/protocol.rs.