History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 59–61 on cd46e56b1709a01b405ac538ae4092a3fb12b36d6f6847690892fa0f7956aeed. 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.