Remove remaining references to SiteMiddleware

docs/getting_started/integrating_into_django.rst

@@ -35,16 +35,12 @@ In your settings file, add the following apps to ``INSTALLED_APPS``:
     'modelcluster',
     'taggit',
 
-Add the following entries to ``MIDDLEWARE``:
+Add the following entry to ``MIDDLEWARE``:
 
 .. code-block:: python
 
-    'wagtail.core.middleware.SiteMiddleware',
     'wagtail.contrib.redirects.middleware.RedirectMiddleware',
 
-.. note::
-   Wagtail is currently incompatible with projects using ``django.contrib.sites.middleware.CurrentSiteMiddleware``, as both this and ``wagtail.core.middleware.SiteMiddleware`` set the attribute ``request.site``.
-
 Add a ``STATIC_ROOT`` setting, if your project does not have one already:
 
 .. code-block:: python

wagtail/contrib/settings/context_processors.py

@@ -57,9 +57,6 @@ def settings(request):
         site = Site.find_for_request(request)
         if site is None:
             # find_for_request() can't determine the site
-            # old SiteMiddleware case
-            # Unittest or email templates might also mock request
-            # objects that don't have a request.site.
             return {}
         else:
             return SettingsProxy(site)

wagtail/core/views.py

@@ -8,8 +8,7 @@ from wagtail.core.models import Page, PageViewRestriction, Site
 
 
 def serve(request, path):
-    # we need a valid Site object corresponding to this request (set in wagtail.core.middleware.SiteMiddleware)
+    # we need a valid Site object corresponding to this request in order to proceed
-    # in order to proceed
     site = Site.find_for_request(request)
     if not site:
         raise Http404

wagtail/project_template/project_name/settings/base.py

@@ -59,7 +59,6 @@ MIDDLEWARE = [
     'django.middleware.clickjacking.XFrameOptionsMiddleware',
     'django.middleware.security.SecurityMiddleware',
 
-    'wagtail.core.middleware.SiteMiddleware',
     'wagtail.contrib.redirects.middleware.RedirectMiddleware',
 ]