History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 45–47 on b64e2537d7028806bc3d1da95b489e1071f40abda62dfbe43d1d038a65115d13. 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.