fix ot_customizer module responsive design

ot_templating/Resources/Public/assets/Backend/style/ot_customizer.css

@@ -2,6 +2,8 @@
 .ot-customizer {
     display: flex;
     flex-direction: row;
+    height: 100%;
+    overflow-y: scroll !important;
 }
 
 .ot-customizer .templates {