WM/Default: Fix few more shutdown issues
WM/Default: Fix few more shutdown issues

Signed-off-by: Denis Oliver Kropp <3fa78fd63dd76ba74a102cf4e1e79303ef9149a1@directfb.org>

jcdubois/DirectFB,kaostao/directfb,sklnet/DirectFB,DirectFB/directfb,kevleyski/directfb,kevleyski/directfb,lancebaiyouview/DirectFB,deniskropp/DirectFB,sklnet/DirectFB,kevleyski/DirectFB-1,lancebaiyouview/DirectFB,deniskropp/DirectFB,mtsekm/test,Distrotech/DirectFB,dfbdok/DirectFB1,sklnet/DirectFB,jcdubois/DirectFB,lancebaiyouview/DirectFB,dfbdok/DirectFB1,jcdubois/DirectFB,kaostao/directfb,mtsekm/test,kevleyski/DirectFB-1,lancebaiyouview/DirectFB,DirectFB/directfb,kevleyski/DirectFB-1,deniskropp/DirectFB,dfbdok/DirectFB1,sklnet/DirectFB,djbclark/directfb-core-DirectFB,kaostao/directfb,mtsekm/test,kevleyski/DirectFB-1,djbclark/directfb-core-DirectFB,kevleyski/directfb,DirectFB/directfb,Distrotech/DirectFB,kevleyski/directfb,djbclark/directfb-core-DirectFB,Distrotech/DirectFB,deniskropp/DirectFB,djbclark/directfb-core-DirectFB