History of Swarm::step 1 change

In crates/backdrop/src/swarm.rs, lines 154–160 on v0.9.7. 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 154,160:crates/backdrop/src/swarm.rs.