fix for scroller

fixed out of array problem when the bg loop should start

Assets/Scripts/BackgroundRoller.cs

@@ -32,7 +32,7 @@ public class BackgroundRoller : MonoBehaviour
 
         if (currentSprite >= bgSprites.Count - 1)
         {
-            currentSprite = -1; //never do this at home kids
+            currentSprite = 0; //never do this at home kids
         }
 
         //if there are sprites left & we are over half the height, we instantiate another sprite at the top