Fix the scrollbar flickering issue for video

- Removes any space between the edges of the
  iframes interior and the video

Author: NyanHelsing

mfr/extensions/video/templates/viewer.mako

@@ -1,3 +1,11 @@
+<style>
+    ## Setting margin and padding to 0 for body fixes the scrollbar flickering issue
+    body {
+        margin: 0;
+        padding: 0;
+    }
+</style>
+
 <video controls height="100%">
   <source src="${url}">
   Your browser does not support the video tag.
@@ -7,4 +15,4 @@
 <script src="/static/js/mfr.child.js"></script>
 <script>
     window.pymChild.sendMessage('embed', 'embed-responsive-16by9');
-</script>
+</script>