Fix leak on real output when using a very recent output

The wallet and the daemon applied different height considerations
when selecting outputs to use. This can leak information on which
input in a ring signature is the real one.

Found and originally fixed by smooth on Aeon.

src/wallet/wallet2.h

@@ -50,7 +50,6 @@
 #include "wallet_errors.h"
 
 #include <iostream>
-#define DEFAULT_TX_SPENDABLE_AGE                               10
 #define WALLET_RCP_CONNECTION_TIMEOUT                          200000
 
 namespace tools