Begin removing several dependencies on Config object

gateway/httpgateway.h

@@ -19,7 +19,7 @@ class HttpGateway : public GatewayInterface
 	uint64_t maxPayloadLength;
 
   public:
-	HttpGateway(const Config &config);
+	HttpGateway(std::string listenaddr, int port, uint64_t maxPayloadLength);
 	bool keepReading() override;
 	void work(RequestWorker &worker) override;
 };