IServerContainer is effectively an IContainer

This relation was not explicitly declared in the class description.

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

lib/public/IServerContainer.php

@@ -54,7 +54,7 @@ use Symfony\Component\EventDispatcher\EventDispatcherInterface;
  * This container holds all ownCloud services
  * @since 6.0.0
  */
-interface IServerContainer {
+interface IServerContainer extends IContainer {
 
 	/**
 	 * The contacts manager will act as a broker between consumers for contacts information and