xml 생성 설정 수정

src/main/java/cokr/xit/foundation/boot/MvcConfig.java

@@ -111,6 +111,7 @@ public class MvcConfig implements WebMvcConfigurer {
 	public MappingJackson2XmlView xmlView() {
 		XmlMapper xmlMapper = new XmlMapper();
 		xmlMapper.configure(ToXmlGenerator.Feature.WRITE_XML_DECLARATION, true);
+		xmlMapper.configure(ToXmlGenerator.Feature.WRITE_XML_1_1, true);
 
 		MappingJackson2XmlView bean = new MappingJackson2XmlView();
 		bean.setContentType("application/xml; charset=UTF-8");