message: refactor: Prefer clean assert over UB in coinstats
diff: @@ -94,7 +94,8 @@ static bool GetUTXOStats(CCoinsView* view, BlockManager& blockman, CCoinsStats&
  {
  LOCK(cs_main);
  assert(std::addressof(g_chainman.m_blockman) == std::addressof(blockman));
  - stats.nHeight = blockman.LookupBlockIndex(stats.hashBlock)->nHeight;
  + const CBlockIndex* block = blockman.LookupBlockIndex(stats.hashBlock);
  + stats.nHeight = Assert(block)->nHeight;
  }
  PrepareHash(hash_obj, stats);
  