1. Solve Docker service not start after restart.
2. Solve a variable not exist error in upgrade thread code.
3. Consider update global.yml before calling kolla-ansible
upgrade to aware of changing of multicast switch in daisy.conf.
Change-Id: I9cddb4614264689d5fe1858249875f950c41a699
Signed-off-by: Zhijiang Hu <hu.zhijiang@zte.com.cn>
86af78213c