Clean unused code for `supports_tenants`

It seems that the `supports_tenants` attr is unused now,
the patch clean up some code related to `supports_tenants`
so that the code can be more readable for devs:)

Closes-Bug: 1417841
Change-Id: Ia3def66b34bf91a4a4e2d7bcb61c5f3be1d16abb

doc/source/quickstart.rst

@@ -243,7 +243,6 @@ process::
         # ObjectStorePanels
         panels = (BasePanels, NetworkPanels, ObjectStorePanels)
         default_panel = 'overview'
-        supports_tenants = True
         ...
 
     horizon.register(Project)

horizon/base.py

@@ -412,13 +412,6 @@ class Dashboard(Registry, HorizonComponent):
         to control whether or not this dashboard should appear in
         automatically-generated navigation. Default: ``True``.
 
-    .. attribute:: supports_tenants
-
-        Optional boolean that indicates whether or not this dashboard includes
-        support for projects/tenants. If set to ``True`` this dashboard's
-        navigation will include a UI element that allows the user to select
-        project/tenant. Default: ``False``.
-
     .. attribute:: public
 
         Boolean value to determine whether this dashboard can be viewed
@@ -432,7 +425,6 @@ class Dashboard(Registry, HorizonComponent):
     panels = []
     default_panel = None
     nav = True
-    supports_tenants = False
     public = False
 
     def __repr__(self):

horizon/templates/horizon/_accordion_nav.html

@@ -4,7 +4,6 @@
 <dl class="nav_accordion">
 {% for dashboard, panel_info in components %}
   {% if user|has_permissions:dashboard %}
-    {% if dashboard.supports_tenants and request.user.authorized_tenants or not dashboard.supports_tenants %}
     <dt {% if current.slug == dashboard.slug %}class="active"{% endif %}>
       {{ dashboard.name }}
       <span class="glyphicon pull-right"></span>
@@ -37,6 +36,5 @@
     {% endfor %}
     </dd>
   {% endif %}
-  {% endif %}
 {% endfor %}
 </dl>

openstack_dashboard/dashboards/project/dashboard.py

@@ -83,7 +83,6 @@ class Project(horizon.Dashboard):
         DatabasePanels,
         DataProcessingPanels,)
     default_panel = 'overview'
-    supports_tenants = True
 
 
 horizon.register(Project)