History of Server::backend 1 change

In crates/oxy-server/src/lib.rs, lines 174–176 on 83d61e803ccd1f6568e03de9cf45b021fd5100c7ff332ef2cc9ec6a58b5e5d75. 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 174,176:crates/oxy-server/src/lib.rs.