message: index: refactor-only: Reuse CChain ref
diff: @@ -60,12 +60,12 @@ bool BaseIndex::Init()
  }
  LOCK(cs_main);
  + CChain& active_chain = m_chainstate->m_chain;
  if (locator.IsNull()) {
  m_best_block_index = nullptr;
  } else {
  - m_best_block_index = m_chainstate->m_blockman.FindForkInGlobalIndex(m_chainstate->m_chain, locator);
  + m_best_block_index = m_chainstate->m_blockman.FindForkInGlobalIndex(active_chain, locator);
  }
  - CChain& active_chain = m_chainstate->m_chain;
  m_synced = m_best_block_index.load() == active_chain.Tip();
  if (!m_synced) {
  bool prune_violation = false;
  