fixed zindex issues on side-by-side diffs

rhodecode/public/css/style.css

@@ -3111,6 +3111,7 b' table.code-browser .submodule-dir {'
     border-radius: 8px 8px 8px 8px;
     box-shadow: 0 2px 2px rgba(0, 0, 0, 0.6);
     -webkit-box-shadow: 0 2px 2px rgba(0, 0, 0, 0.6);
+    z-index: 100000;
 }
 
 .hl-tip-box {

rhodecode/templates/email_templates/changeset_comment.html

@@ -16,4 +16,3 b''
 <p>${_('Description')}:<br/>
 ${h.shorter(message, 256)}
 </p>
-