Removes reference to redirect extension

Removes all references to the redirect extension which
was previously already removed. Local testing didn't pick this
up because of stale pyc file.

Change-Id: Ia74a93da960736c450378dcfedbe858c145c07a3

doc/source/conf.py

@@ -27,8 +27,7 @@ sys.path.insert(0, os.path.abspath('.'))
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['redirect',
-              'sphinx.ext.autodoc',
+extensions = ['sphinx.ext.autodoc',
               'sphinx.ext.todo',
               'sphinx.ext.viewcode',
               'oslosphinx',