History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 59–61 on 66fd9d6b145201f17500e55103fc78c7608571da3222858c350fa6d0fe925006. 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.