History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 59–61 on 8475176972e8da38802f739d8092e0544f1e9cf120a6b4638ec3667683828018. 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.