NEWS: Remove spurious period

All other entries in the release notes omit the leading period,
and so should this one in order to maintain consistency.

docs/news.html.in

@@ -70,7 +70,7 @@
           <li>qemu: Enable mount namespace<br/>
           To avoid funny races with udev relabelling devices under our hands and
           to enhance security, libvirt now spawns each qemu process with its own
-          <code>/dev</code>.</li>
+          <code>/dev</code></li>
         </ul>
       </li>
     </ul>