message: Fix ATXOs rescanning.
  On reprocessing an anon transaction, ATXOs were not checked if they are owned by a wallet key. Might fix
  Every block must be scanned to rebuild the anonymous transaction cache. Therefore nTimeFirstKey (time of first wallet key) is not considered as filter.
diff: @@ -1303,27 +1303,16 @@ int CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate)
  };
  int ret = 0;
  - int64_t nTimeFirstKeyTmp = nTimeFirstKey;
  int nCurBestHeight = nBestHeight;
  fReindexing = true;
  - // When scanning from a certain height, people could be interested in rebuilding stealth address and anonymous transaction cache.
  - if(pindexStart->nHeight > 1)
  - nTimeFirstKey = pindexStart->nTime;
  -
  + // Note: Every block is scanned to rebuild the anonymous transaction cache
  + // therefore nTimeFirstKey (time of first wallet key) is not considered as filter
  CBlockIndex* pindex = pindexStart;
  {
  LOCK2(cs_main, cs_wallet);
  while (pindex)
  {
  - // no need to read and scan block, if block was created before
  - // our wallet birthday (as adjusted for block time variability)
  - if (nTimeFirstKey && (pindex->nTime < (nTimeFirstKey - 7200)))
  - {
  - pindex = pindex->pnext;
  - continue;
  - };
  -
  CBlock block;
  block.ReadFromDisk(pindex, true);
  nBestHeight = pindex->nHeight;
  @@ -1337,8 +1326,6 @@ int CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate)
  };
  } // cs_main, cs_wallet
  - // Reset nTimeFirstKey
  - nTimeFirstKey = nTimeFirstKeyTmp;
  nBestHeight = nCurBestHeight;
  fReindexing = false;
  @@ -3016,10 +3003,9 @@ bool CWallet::ProcessAnonTransaction(CWalletDB *pwdb, CTxDB *ptxdb, const CTrans
  && spentKeyImage.inputNo == i)
  {
  if (fDebugRingSig)
  - LogPrintf("found matching spent key image - txn has been processed before\n");
  - return UpdateAnonTransaction(ptxdb, tx, blockHash);
  - };
  -
  + LogPrintf("found matching spent key image - txn has been processed before, reprocessing.\n");
  + }
  + else {
  if (TxnHashInSystem(ptxdb, spentKeyImage.txnHash))
  {
  return error("%s: Error input %d keyimage %s already spent.", __func__, i, HexStr(vchImage).c_str());
  @@ -3031,6 +3017,7 @@ bool CWallet::ProcessAnonTransaction(CWalletDB *pwdb, CTxDB *ptxdb, const CTrans
  // -- keyimage is in db, but invalid as does not point to a known transaction
  // could be an old mempool keyimage
  // continue
  + }
  };
  