message: Return `true` when signature was added to pending collection.
diff: @@ -65,7 +65,8 @@ impl PendingSignatures {
  return false;
  }
  // Add the pending signature.
  - sigs.insert(block_hash, signature).is_some()
  + sigs.insert(block_hash, signature);
  + true
  }
  pub(super) fn remove(
  