Update keystone_authtoken config in senlin installation doc

[Duc Truong]

The configuratiopn for keystone_authtoken in Senlin installation doc (https://docs.openstack.org/senlin/latest/install/install-source.html#install-senlin-server) is incorrect.

It should be something like this:

[keystone_authtoken]
service_token_roles_required = True
auth_type = password
user_domain_name = Default
project_domain_name = Default
project_name = service
password = secretsecret
username = senlin
www_authenticate_uri = http://10.0.20.10/identity/v3
auth_url = http://10.0.20.10/identity
cafile = /opt/stack/data/ca-bundle.pem

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/668225
Committed: https://git.openstack.org/cgit/openstack/senlin/commit/?id=074ee9f7fe58b4ba3143d4e8b592d7486e7d950d
Submitter: Zuul
Branch: master

commit 074ee9f7fe58b4ba3143d4e8b592d7486e7d950d
Author: Duc Truong <email address hidden>
Date: Fri Jun 28 18:10:44 2019 +0000

    Fix keystone_authtoken config in docs

    The keystone_authtoken configuration in the installatiion documentation
    are incorrect. Updated the documentation to use correct values that
    work in devstack for senlin.

    Change-Id: I9ee7e6c9d5e8e86dcefd459599ebee5f151a612a
    Closes-Bug: #1834515

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/senlin 8.0.0.0rc1 release candidate.