message: Return error when failed to accept wtx to mempool.
diff: @@ -3915,8 +3915,7 @@ bool CWallet::CommitTransaction(CTransactionRef tx, mapValue_t mapValue, std::ve
  // Broadcast
  if (!wtx.AcceptToMemoryPool(maxTxFee, state)) {
  - LogPrintf("CommitTransaction(): Transaction cannot be broadcast immediately, %s\n", FormatStateMessage(state));
  - // TODO: if we expect the failure to be long term or permanent, instead delete wtx from the wallet and return failure.
  + return error("CommitTransaction(): Transaction cannot be broadcast immediately, %s\n", FormatStateMessage(state));
  } else {
  wtx.RelayWalletTransaction(connman);
  }
  