Ridotto tempo rotazione banner a 20sec

Signed-off-by: Riccardo Di Dato <r.didato@asdynamics.it>

public/getBanner.php

@@ -48,7 +48,7 @@ Creation Date:	02/mar/2016
 			var rand = Math.floor((Math.random() * 100) + 1);
 			setTimeout(function () { 
 				bannerRoll('<?php echo $banner->id;?>',<?php echo $position; ?>,<?php echo $category?>);
-			},60000+rand);
+			},20000+rand);
 		</script>
 		<?php 
 	}