History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 107–109 on dd327d76062d8685bec98f4eb43ae719b4e1c55f8ffbcc87b3c4da72dda04705. 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.