History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 59–61 on 53a0fb2e4ac6ce0fd5f7c4df7bb034fb9ba0c67af0d337454077b5afd2e9971d. 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.