fix a broken link that jens pointed out

svn:r4797

doc/tor-doc-unix.html

@@ -55,7 +55,7 @@ href="tor-doc-server.html">Configuring a server</a> guide.</b>
 
 <p>
 The latest release of Tor can be found on the <a
-href="download.html">download</a> page. We have packages for Debian,
+href="/download.html">download</a> page. We have packages for Debian,
 Red Hat, Gentoo, *BSD, etc there too.
 </p>