The WSGIScriptAlias in ``/etc/apache2/sites-available/ceilometer.conf``
shoule be ``/usr/lib/python2.7/dist-packages/ceilometer/api/app.wsgi``
Closes-Bug: #1644972
Change-Id: Id795520b1330114243c6045162abad6d4d1f1ae8
Signed-off-by: liyuenan <liyuenan@huawei.com>