TT#104162 Improve free space usage on ngcp-panel content section

The free space reservation (top/bottom margin) for 'content' section
was huge and was wasting a lot of free space for 4K+ monitors.
Also it is heavily visible for zoomed page 120%+ and triggers
often unnecessary vertical scrolling.

Let's use free space in better way.

Change-Id: I3c106639018199976bb0cbf6937665939cec61a2

share/static/css/application.css

@@ -2084,8 +2084,8 @@ Layout: Content
 
 ------------------------------------------------------------------- */
 #content {
-  margin-top: 3em;
-  margin-bottom: 8em;
+  margin-top: 1em;
+  margin-bottom: 2em;
 }
 #content .row {
   margin-top: 1em;