History of base64url 1 change

In crates/hub/tests/backups.rs, lines 336–352 on diffusion-pin-bookmark. 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 336,352:crates/hub/tests/backups.rs.