History of HubBackend::block 2 changes

In crates/hub/src/protocol.rs, lines 102–104 on 787632570bf924647f982368186b693468134d3617cec41ca11ed19451205d46. 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 102,104:crates/hub/src/protocol.rs.