History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 107–109 on 8306eca4e4a3347a39de4baeaa83e7c7270fa356998bd66b6923b4338a5d2373. 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 107,109:crates/hub/src/protocol.rs.