Bugfix: Adjusting systemTime correctly

VIPSWeb/static/js/frontpage.js

@@ -70,7 +70,7 @@ var filteredObservations;
  */
 function cacheObservations(callback)
 {
-	var systemTime = moment().subtract(settings.systemTimeOffsetMonths,"months");
+	var systemTime = moment().add(settings.systemTimeOffsetMonths,"months");
     var from = systemTime.format("YYYY") + "-01-01"; // XXXX-01-01
     var to = systemTime.format("YYYY-MM-DD"); 
     var uuidParam = settings.userUuid != null ? "&userUUID=" + settings.userUuid : "";