message: Replace pattern match with elvis operator.
diff: @@ -154,9 +154,7 @@ impl BlockCache {
  }
  fn get(&self, hash: &BlockHash) -> Option<Block> {
  - match self.blocks.get(hash) {
  - None => None,
  - Some(block_header) => {
  + let block_header = self.blocks.get(hash)?;
  let mut block = Block::from_header(block_header.clone());
  if let Some(proofs) = self.proofs.get(hash) {
  for (pub_key, sig) in proofs {
  @@ -165,8 +163,6 @@ impl BlockCache {
  }
  Some(block)
  }
  - }
  - }
  /// Inserts new block to the cache.
  /// Caches block's finality signatures as well.
  