defaulted new parameters in modified functions

src/cryptonote_core/account.h

@@ -31,7 +31,7 @@ namespace cryptonote
   {
   public:
     account_base();
-    void generate(const crypto::secret_key& recovery_key, bool recover);
+    void generate(const crypto::secret_key& recovery_key = crypto::secret_key(), bool recover = false);
     const account_keys& get_keys() const;
     std::string get_public_address_str();
 

src/wallet/wallet2.h

@@ -97,7 +97,7 @@ namespace tools
       END_SERIALIZE()
     };
 
-    void generate(const std::string& wallet, const std::string& password, const crypto::secret_key& recovery_param, bool recover = false);
+    void generate(const std::string& wallet, const std::string& password, const crypto::secret_key& recovery_param = crypto::secret_key(), bool recover = false);
     void load(const std::string& wallet, const std::string& password);
     void store();
     cryptonote::account_base& get_account(){return m_account;}