Added missing application/xml to stringConverted for sitemap XML controllers

src/main/java/org/genesys2/spring/config/WebConfiguration.java

@@ -264,7 +264,7 @@ public class WebConfiguration implements WebMvcConfigurer {
 
 	public StringHttpMessageConverter stringConverter() {
 		final StringHttpMessageConverter stringConverter = new StringHttpMessageConverter(Charsets.UTF_8);
-		stringConverter.setSupportedMediaTypes(Arrays.asList(MediaType.TEXT_PLAIN, MediaType.TEXT_HTML, MediaType.APPLICATION_JSON));
+		stringConverter.setSupportedMediaTypes(Arrays.asList(MediaType.TEXT_PLAIN, MediaType.TEXT_HTML, MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML));
 		return stringConverter;
 	}