simplewallet: don't complain about payment id on pool mined blocks

Those use the extra nonce without a payment id

src/simplewallet/simplewallet.cpp

@@ -4157,10 +4157,11 @@ void simple_wallet::on_money_received(uint64_t height, const crypto::hash &txid,
     if (find_tx_extra_field_by_type(tx_extra_fields, extra_nonce))
     {
       crypto::hash8 payment_id8 = crypto::null_hash8;
+      crypto::hash payment_id = crypto::null_hash;
       if (get_encrypted_payment_id_from_tx_extra_nonce(extra_nonce.nonce, payment_id8))
         message_writer() <<
           tr("NOTE: this transaction uses an encrypted payment ID: consider using subaddresses instead");
-      else
+      else if (get_payment_id_from_tx_extra_nonce(extra_nonce.nonce, payment_id))
         message_writer(console_color_red, false) <<
           tr("WARNING: this transaction uses an unencrypted payment ID: consider using subaddresses instead");
    }