One newline is enough.

git-svn-id: https://develop.svn.wordpress.org/trunk@19684 602fd350-edb4-49c9-b593-d223f7449a82

wp-admin/css/colors-classic.dev.css

@@ -1002,7 +1002,6 @@ table.widefat .spam a:hover,
 	border-color: #5589AA !important;
 }
 
-
 .wp-editor-wrap .wp_themeSkin table.mceSplitButton td {
 	background-color: #cfdfe9; /* Fallback */
 	background-image: -ms-linear-gradient(bottom, #cfdfe9, #fff); /* IE10 */
@@ -1604,7 +1603,6 @@ table.widefat .spam a:hover,
 }
 /* end screen icons */
 
-
 /* Diff */
 table.diff .diff-deletedline {
 	background-color: #fdd;