Revert "Load core modules also when bootstrapping the CLI"

This reverts commit f12473d34b.

The CLI must not load core modules, i.e. setup.

library/Icinga/Application/Cli.php

@@ -43,8 +43,7 @@ class Cli extends ApplicationBootstrap
             ->parseBasicParams()
             ->setupLogger()
             ->setupResourceFactory()
-            ->setupModuleManager()
-            ->loadCoreModules();
+            ->setupModuleManager();
     }
 
     protected function setupLogging()