paper: overlapping of section title on help pages (issue4051)

Now there will be no overlap lines between various section title
on help pages. http://selenic.com/repo/hg/help/config

mercurial/templates/static/style-paper.css

@@ -168,7 +168,7 b' pre { margin: 0; }'
 h2 { font-size: 120%; border-bottom: 1px solid #999; }
 h2 a { color: #000; }
 h3 {
-  margin-top: -.7em;
+  margin-top: +.7em;
   font-size: 100%;
 }