Small fix to fullscreen mode where scrolling would scroll the background dashboard & page header

src/css/less/grafana.less

@@ -117,8 +117,9 @@
 }
 
 .dashboard-fullscreen {
-  .row-control-inner {
-    display: none;
+  .main-view-container {
+    height: 0;
+    overflow: hidden;
   }
 }