Fix documentation of control host bootstrap

Change-Id: Ie1d7753d9061b587caa5e150f72b51658a887318

doc/source/deployment.rst

@@ -20,7 +20,7 @@ Ansible Control Host
 Before starting deployment we must bootstrap the Ansible control host.  Tasks
 performed here include:
 
-- Install Ansible and role dependencies from Ansible Galaxy.
+- Install required Ansible roles from Ansible Galaxy.
 - Generate an SSH key if necessary and add it to the current user's authorised
   keys.
 - Install Kolla Ansible locally at the configured version.