Updated tinderbox link

git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@2080 f882894a-f735-0410-b71e-b25c423dba1c

doc/developer-guidelines.sgml

@@ -678,7 +678,7 @@ all the current tests and report an overall success rate.
 </para>
 
 <para>
-See the <ulink url="http://tinderbox.altinity.org">Nagios Plugins Tinderbox server</ulink>
+See the <ulink url="http://tinderbox.opsera.com">Nagios Plugins Tinderbox server</ulink>
 for the daily test results.
 </para>