History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 59–61 on c0095389312bf1b2c80f27971c055382946928e880bba8c1da8329e3d38239d6. 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.