move TunnelHopVisitor inside Tunnel class

Signed-off-by: R4SAS <r4sas@i2pmail.org>

libi2pd/Tunnel.h

@@ -44,9 +44,6 @@ namespace tunnel
 	const size_t I2NP_TUNNEL_MESSAGE_SIZE = TUNNEL_DATA_MSG_SIZE + I2NP_HEADER_SIZE + 34; // reserved for alignment and NTCP 16 + 6 + 12
 	const size_t I2NP_TUNNEL_ENPOINT_MESSAGE_SIZE = 2*TUNNEL_DATA_MSG_SIZE + I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE + 28; // reserved for alignment and NTCP 16 + 6 + 6
 
-	/** function for visiting a hops stored in a tunnel */
-	typedef std::function<void(std::shared_ptr<const i2p::data::IdentityEx>)> TunnelHopVisitor;
-
 	enum TunnelState
 	{
 		eTunnelStatePending,
@@ -70,6 +67,9 @@ namespace tunnel
 
 		public:
 
+			/** function for visiting a hops stored in a tunnel */
+			typedef std::function<void(std::shared_ptr<const i2p::data::IdentityEx>)> TunnelHopVisitor;
+
 			Tunnel (std::shared_ptr<const TunnelConfig> config);
 			~Tunnel ();