Revirt removing REST API loading
Revirt removing REST API loading

Since dashboard plugins are loaded from its panels at first,
REST API should be loaded from panels.py or its near module.

Change-Id: I88ca6935275a83969d956a8493eb1d465fd38e7d

openstack/magnum-ui,openstack/magnum-ui,openstack/magnum-ui,openstack/magnum-ui