Change port of docker registry

The port of docker registry is conflict with keystone.
So we need to change port of docker registry.

Change-Id: If15c0caf76b5406f590b05030e43d65ca14c8788
Signed-off-by: pengdake <19921207pq@gmail.com>

doc/source/admin/image-building.rst

@@ -157,7 +157,7 @@ use ``--registry`` flag:
 
 .. code-block:: console
 
-   kolla-build --registry 172.22.2.81:5000 --push
+   kolla-build --registry 172.22.2.81:4000 --push
 
 Build OpenStack from source
 ===========================
@@ -532,7 +532,7 @@ Kolla-ansible with Local Registry
 ---------------------------------
 
 To make kolla-ansible pull images from a local registry, set
-``"docker_registry"`` to ``"172.22.2.81:5000"`` in
+``"docker_registry"`` to ``"172.22.2.81:4000"`` in
 ``"/etc/kolla/globals.yml"``. Make sure Docker is allowed to pull images from
 insecure registry. See
 `Docker Insecure Registry

tools/start-registry

@@ -3,6 +3,6 @@
 docker run -d \
     --name registry \
     --restart=always \
-    -p 5000:5000 \
+    -p 4000:5000 \
     -v registry:/var/lib/registry \
     registry:2