message: progress: display "Downloading 1 crate" instead of "Downloading 1 crates"
diff: @@ -816,7 +816,12 @@ impl<'a, 'cfg> Downloads<'a, 'cfg> {
  return Ok(());
  }
  }
  - let mut msg = format!("{} crates", self.pending.len());
  + let pending = self.pending.len();
  + let mut msg = if pending == 1 {
  + format!("{} crate", pending)
  + } else {
  + format!("{} crates", pending)
  + };
  match why {
  WhyTick::Extracting(krate) => {
  msg.push_str(&format!(", extracting {} ...", krate));
  