History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 59–61 on f3e5e2bc78e936e8d327871445ab4baeb5a2de73081514efa21f26a11c47d4aa. 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 59,61:crates/hub/src/protocol.rs.