added overrides

Author: mathieucarbou

src/AsyncEventSource.h

@@ -316,7 +316,7 @@ class AsyncEventSourceResponse : public AsyncWebServerResponse {
 public:
   AsyncEventSourceResponse(AsyncEventSource *server);
   void _respond(AsyncWebServerRequest *request);
-  size_t _ack(AsyncWebServerRequest *request, size_t len, uint32_t time);
+  size_t _ack(AsyncWebServerRequest *request, size_t len, uint32_t time) override;
   bool _sourceValid() const {
     return true;
   }

src/AsyncWebSocket.h

@@ -468,7 +468,7 @@ class AsyncWebSocketResponse : public AsyncWebServerResponse {
 public:
   AsyncWebSocketResponse(const String &key, AsyncWebSocket *server);
   void _respond(AsyncWebServerRequest *request);
-  size_t _ack(AsyncWebServerRequest *request, size_t len, uint32_t time);
+  size_t _ack(AsyncWebServerRequest *request, size_t len, uint32_t time) override;
   bool _sourceValid() const {
     return true;
   }