History of HubBackend::caller 2 changes

In crates/hub/src/protocol.rs, lines 58–77 on 07b1a5bbf48143f80d47c65ddb869293b6e4cd55d5b78b0c2534c5e430a6e77b. 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 58,77:crates/hub/src/protocol.rs.