History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 45–47 on f5c4433783335420787bf7c185fdc00ce8b856d2b57945ae841c88e94e8537ec. 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 45,47:crates/hub/src/protocol.rs.