fix response `content-type` is not set if access without access token

Kairlec

2023-05-15 ca103731c721aae3f5f622e58c679ed5c09fd9e9

 src/main/java/com/genersoft/iot/vmp/vmanager/streamProxy/StreamProxyController.java

@@ -25,7 +25,7 @@
 */
@Tag(name = "拉流代理", description = "")
@Controller
@CrossOrigin

@RequestMapping(value = "/api/proxy")
public class StreamProxyController {