fix(Setup) clear statcache after deleting route.cache file

Change-Id: I2c6e73d879a621c05aa21899495001981af00bea
Reviewed-on: http://gerrit.tine20.com/customers/18729
Tested-by: Jenkins CI (http://ci.tine20.com/) <tine20-jenkins@metaways.de>
Reviewed-by: Paul Mehrer <p.mehrer@metaways.de>

tine20/Setup/Controller.php

@@ -2813,6 +2813,7 @@ public function clearCache()
                 unlink($directoryIterator->getPathname());
             }
         }
+        clearstatcache();
 
         // deactivate cache again
         Tinebase_Core::setupCache(FALSE);