Update AsyncJson.h (me-no-dev#604)

remove extra #endif that should have been dropped as part of me-no-dev@59066bd

Author: atanisoft

src/AsyncJson.h

@@ -166,7 +166,6 @@ class PrettyAsyncJsonResponse: public AsyncJsonResponse {
 		return len;
 	}
 };
-#endif
 
 typedef std::function<void(AsyncWebServerRequest *request, JsonVariant &json)> ArJsonRequestHandlerFunction;