Fix to allow using the ULS when it is bigger than the viewport

Small fix that make global scrolling to affect the ULS (using absolute positioning instead of fixed).
It solves the problem behind bug 39414 without the need for making the window draggable.

Change-Id: Icc3ca81c4b48040b38a5efb42422bdb53e0e2422

lib/jquery.uls/css/jquery.uls.css

@@ -6,7 +6,7 @@
 }
 
 .uls-menu {
-	position: fixed;
+	position: absolute;
 	z-index: 1000;
 	display: none;
 	min-width: 715px;
@@ -213,4 +213,4 @@ span#languagefilter-clear {
 
 #search-input-block {
 	position: relative;
-}
+}