Fix alignment of next/prev links in offline style

With the old value, they were placed above the
header bar. Moving them a few pixels below looks
less broken.

Pick-to: 6.2 6.3 5.15
Change-Id: Iddd9d5e0b5c199fe35a9c8b8a7cac9a472901a21
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

doc/global/template/style/offline.css

@@ -147,7 +147,7 @@ Top navigation
     display: block;
     position: relative;
     text-align: right;
-    top: -47px;
+    top: -30px;
     float: right;
     height: 20px;
     z-index: 1;