fix iframe overflow behavior (bis)

ot_stats/Resources/Public/assets/Backend/style/ot_stats.css

@@ -1,10 +1,8 @@
 
-body {
-    overflow-y: scroll;
-}
-
 .ot-stats {
     margin: 20px 3%;
+    overflow-y: scroll;
+    height: 100%;
 }
 
 .statsConfirmationPanel {