Fixed the problem that "vnflcm_mgmt_driver = vnflcm_noop" does not exist
in /etc/tacker/tacker.conf after installing the tacker.
In setup.cfg, change vnflcm_drivers to vnflcm_driver.
In etc/config-generator.conf, add "namespace = tacker.vnflcm.vnflcm_driver".
Closes-Bug: #1918232
Change-Id: I50ffb4c96837599dcb0d04dd673e0c4681ffedfa