remove CWallet::AddReserveKey which is never used

src/wallet.cpp

@@ -1671,21 +1671,6 @@ void CWallet::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool)
     }
 }
 
-int64_t CWallet::AddReserveKey(const CKeyPool& keypool)
-{
-    {
-        LOCK2(cs_main, cs_wallet);
-        CWalletDB walletdb(strWalletFile);
-
-        int64_t nIndex = 1 + *(--setKeyPool.end());
-        if (!walletdb.WritePool(nIndex, keypool))
-            throw runtime_error("AddReserveKey() : writing added key failed");
-        setKeyPool.insert(nIndex);
-        return nIndex;
-    }
-    return -1;
-}
-
 void CWallet::KeepKey(int64_t nIndex)
 {
     // Remove from key pool

src/wallet.h

@@ -263,7 +263,6 @@ public:
 
     bool NewKeyPool();
     bool TopUpKeyPool(unsigned int kpSize = 0);
-    int64_t AddReserveKey(const CKeyPool& keypool);
     void ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool);
     void KeepKey(int64_t nIndex);
     void ReturnKey(int64_t nIndex);