History of Settings::usable 2 changes

In crates/hub/src/signin.rs, lines 100–102 on 2c31915f5c895708d14d724527c202339c80b97ac4a68f02efc68e40c5fb4903. 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 100,102:crates/hub/src/signin.rs.