Adapt bgp daemon to run properly for testcase3

Adapt bgp daemon to run properly for testcase3

Since apex includes a new version of zrpcd compatible with Carbon
and Nitrogen [0], an adaptation is needed for bgp daemon enabling
and running within testcase3

Note that zrpcd run now as a process and not as a service

JIRA: SDNVPN-172

[0] https://jira.opnfv.org/projects/APEX/issues/APEX-508

Change-Id: Ia0ec4ab0f15ecf3d5c76c5fa541fe8338762ecaf
Signed-off-by: tomsou <soth@intracom-telecom.com>
(cherry picked from commit e1372d3c4955a92f36bfb50ae5925dac2fc0b89c)