fixed result xml sorting

src/test/java/it/unibz/inf/isochrone/network/RuntimeComplex.java

@@ -57,7 +57,7 @@ public final class RuntimeComplex {
 		86400	// 1 day (in sec)
 	};
 	private static Map<Integer, TestParameters> datasets = new TreeMap<>();
-	private static Map<String, Map<String, Long>> runtimes = new HashMap<>();
+	private static Map<String, Map<String, Long>> runtimes = new TreeMap<>();
 
 	// Launcher method (main method) for visualVM