Increase wallet default keypool size to 1000.

Author: gmaxwell

src/wallet/wallet.h

@@ -40,7 +40,7 @@ extern unsigned int nTxConfirmTarget;
 extern bool bSpendZeroConfChange;
 extern bool fWalletRbf;
 
-static const unsigned int DEFAULT_KEYPOOL_SIZE = 100;
+static const unsigned int DEFAULT_KEYPOOL_SIZE = 1000;
 //! -paytxfee default
 static const CAmount DEFAULT_TRANSACTION_FEE = 0;
 //! -fallbackfee default