Description of problem:
`satellite-change-hostname` advises to use "foreman-installer --capsule-parent-fqdn ..." on capsules, but that option does not exist


Version-Release number of selected component (if applicable):
satellite-6.3.0-21.0.beta.el7sat.noarch
satellite-common-6.3.0-21.0.beta.el7sat.noarch


How reproducible:
always


Steps to Reproduce:
1. Rename satellite which have some external capsule
   [root@sat630 ~]# satellite-change-hostname sat630-fake.example.com -u admin --password changeme
2. Use steps it prints on the capsule (first reregister and then rerun installer on capsule)


Actual results:
[root@sat630 ~]# satellite-change-hostname sat630-fake.example.com -u admin --password changeme
[...]
**** Hostname change complete! **** 
IMPORTANT:

  If you want to use custom certificates, re-run the foreman-installer with custom certificate options.

  You will have to install the new bootstrap rpm and reregister all clients and Capsules with subscription-manager
  (update organization and environment arguments appropriately):

  yum remove -y katello-ca-consumer*
  rpm -Uvh http://sat630-fake.example.com/pub/katello-ca-consumer-latest.noarch.rpm
  subscription-manager register --org="Default_Organization" --environment="Library" --force

  Then reattach subscriptions to the client(s) and run:

  subscription-manager refresh
  yum repolist


  On all Capsules, you will need to re-run the foreman-installer with this command:

  foreman-installer --capsule-parent-fqdn sat630-fake.example.com \
                                  --foreman-proxy-foreman-base-url  https://sat630-fake.example.com \
                                  --foreman-proxy-trusted-hosts sat630-fake.example.com

  Short hostnames have not been updated, please update those manually.

Now on capsule after reregistration:

[root@caps630 ~]# foreman-installer --capsule-parent-fqdn sat630-fake.example.com \
>                                   --foreman-proxy-foreman-base-url  https://sat630-fake.example.com \
>                                   --foreman-proxy-trusted-hosts sat630-fake.example.com
ERROR: Unrecognised option '--capsule-parent-fqdn'


Expected results:
When you use "--foreman-proxy-content-parent-fqdn" instead of "--capsule-parent-fqdn" it seems to work.