History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 59–61 on b1e92a6233eea163459042345e77f8b0c082c4a31e01070450ff247bee4b7541. 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.