Fix docs - do not mention the old, deprecated CLI clients

Change-Id: If4c78c5ccefc6ff987b70509379dd91588eeea70
Signed-off-by: Radosław Piliszek <radoslaw.piliszek@gmail.com>

doc/source/user/quickstart.rst

@@ -538,11 +538,11 @@ If error occurs during execution, refer to
 Using OpenStack
 ~~~~~~~~~~~~~~~
 
-#. Install basic OpenStack CLI clients:
+#. Install the OpenStack CLI client:
 
    .. code-block:: console
 
-      pip install python-openstackclient python-glanceclient python-neutronclient
+      pip install python-openstackclient
 
 #. OpenStack requires an openrc file where credentials for admin user
    are set. To generate this file: