Keystone uwsgi set lazy-apps=true

Keystone had a problem where there was a memcached socket
opened very early on startup which then got shared between
worker processes when running under uwsgi. This can be
prevented by setting lazy-apps so this is the recommended
setting.

See http://uwsgi-docs.readthedocs.io/en/latest/ThingsToKnow.html

"""uWSGI tries to (ab)use the Copy On Write semantics of the
fork() call whenever possible. By default it will fork after
having loaded your applications to share as much of their
memory as possible. If this behavior is undesirable for some
reason, use the lazy-apps option. This will instruct uWSGI to
load the applications after each worker’s fork(). Beware as
there is an older options named lazy that is way more invasive
and highly discouraged (it is still here only for backward
compatibility) """

Change-Id: I6f271dc906528f0c86060452deaf15df81b267d2
Related-Bug: 1600394

lib/keystone

@@ -338,6 +338,8 @@ function configure_keystone {
             iniset "$file" uwsgi buffer-size 65535
             # Make sure the client doesn't try to re-use the connection.
             iniset "$file" uwsgi add-header "Connection: close"
+            # This ensures that file descriptors aren't shared between processes.
+            iniset "$file" uwsgi lazy-apps true
         done
     fi