Keep the Link annotation's data URL on one line

Fixes #6278.

web/annotations_layer_builder.css

@@ -60,6 +60,5 @@
 }
 
 .annotationLayer .annotLink > a /* -ms-a */  {
-  background: url("data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAA\
-                   LAAAAAABAAEAAAIBRAA7") 0 0 repeat;
+  background: url("data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7") 0 0 repeat;
 }