Merge pull request #1602 from lhuang04/file_read_callback_prototype_mismatch

Fix prototype mismatch for function 'file_read_callback'

src/HttpServer.h

@@ -242,7 +242,7 @@ private:
 };
 
 ssize_t file_read_callback(nghttp2_session *session, int32_t stream_id,
-                           uint8_t *buf, size_t length, int *eof,
+                           uint8_t *buf, size_t length, uint32_t *data_flags,
                            nghttp2_data_source *source, void *user_data);
 
 } // namespace nghttp2