package.xml: update maintainer email

Signed-off-by: Johannes Meyer <[email protected]>

package.xml

@@ -7,7 +7,7 @@
  thus offering an easy and fast development process.
  </description>
  <author>Sylvain Joyeux/[email protected]</author>
- <maintainer email="orocos-dev@lists.mech.kuleuven.be">Orocos Developers</maintainer>
+ <maintainer email="orocos-dev@orocos.org">Orocos Developers</maintainer>
  <license>GPL v2 or later</license>
 
  <url>https://rock-robotics.org/documentation/orogen</url>