Relocating flavors panel to a different dashboard via Pluggable Settings causes TemplateSyntaxError

[Jerome]

Steps to reproduce:

@Openstack Rocky

1 Change PANEL_DASHBOARD = 'admin' to PANEL_DASHBOARD = 'project' in openstack_dashboard/enabled/_2150_admin_flavors_panel.py
2 Log into Horizon. The menu shows up in Project > Compute instead of Admin > Compute
3 Click on the Flavors menu link.

Result:
=> An unexpected error has occurred. Try refreshing the page. If that doesn't help, contact your local administrator.
=> In the apache log we find:
ERROR horizon.tables.base Error while rendering table rows
{...Stack trace ...}
TemplateSyntaxError: u'flavors' is not a registered namespace inside 'horizon:admin'

Expected Result:
The flavors panel

i.e. : Logged in with a domain admin account

Full trace: http://paste.openstack.org/show/780567/