Rudder

On debian, when upgrading from 5 to 6 we switch de wsgi dependency from relay to webapp.
So the upgrade goies like this:

*something*
install webapp
->unpack webapp
->install relay
--> unpack relay
--> postinst
----> restart apache
*something*
->end install webapp

The apache restart fails since the conf files using wsgi from webapp are already unpacked but the module itself is not loaded at relay install time.
Since relay can be install explicitly without webapp, we should not change its packaging.

An easy workaround might be forcing a "pre-depends" on rudder-server-relay within the rudder-webapp control file. This way, the install of rudder-webapp will only start after the relay is fully installed and so, the webapp conf files using wsgi should not be unpacked too soon.