Reduce line num padding

Bug: Issue 5426
Change-Id: If7f4056780f55b01ad9295e8cd6b6306d162ab34
diff --git a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html
index 159f27c..848de56 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html
+++ b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html
@@ -106,7 +106,7 @@
         display: inline-block;
         color: #666;
         content: attr(data-value);
-        padding: 0 .75em;
+        padding: 0 .5em;
         text-align: right;
         width: 100%;
       }