History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 107–109 on 15d3f6f7871b9ba24296599a30f4188cde40d8831dff7bdaad16c717bfadd9f4. 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.