Hide constructor for static helper

hapi-fhir-server/src/main/java/ca/uhn/fhir/rest/server/ServletRequestTracing.java

@@ -16,6 +16,8 @@ public class ServletRequestTracing {
 	private static final Logger ourLog = LoggerFactory.getLogger(ServletRequestTracing.class);
 	public static final String ATTRIBUTE_REQUEST_ID = ServletRequestTracing.class.getName() + '.' + Constants.HEADER_REQUEST_ID;
 
+	ServletRequestTracing() { }
+	
 	/**
 	 * Assign a tracing id to this request, using
 	 * the X-Request-ID if present and compatible.