fix for BUG 766 - failing IT because of new dependency

- added org.opendaylight.controller.thirdparty:nagasena dependency for pax
- cleaned deps already included in TestHelper

Change-Id: Ie36bc3b0055b9db7b2b5617fad51801917d28aaf
Signed-off-by: Michal Rehak <mirehak@cisco.com>