History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 49–51 on 42fa95540468b40f1710f40f1a79b1bea010c68de2bf9551876f2134644f8e09. 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.