History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 49–51 on 3d1e74cdac76b716b793ea7d5f20f365e4bce8889818e7678be4a64d626a84bc. 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 49,51:crates/hub/src/protocol.rs.