Remove box shadow

![remove box shadow at sonata collection delete button](http://i5.minus.com/jb1vODTaDGKiPT.jpg)
Remove box shadow at sonata collection delete button

Resources/public/css/layout.css

@@ -265,6 +265,7 @@ div.sonata-medium-date div {
 
 .sonata-collection-delete {
     float: left;
+    box-shadow: none;
 }
 
 .no-js .sonata-collection-add, .no-js .sonata-collection-delete {