Http Server: jolokia API should return 404 when there is no jvm

Similiar to the jvm API, the jolokia API should return 404 if no jvm is
available and not server error.

This adds a check that the jvm is available before attempting to use it
and if not throw a 404 not found exception.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
apps: update to latest

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>