Description of problem:
hammer in 6.2 and older did not validate SSL certificates and the installer generated the global config with `host: https://localhost`:

# cat /etc/hammer/cli.modules.d/foreman.yml 
:foreman:
  # Enable/disable foreman commands
  :enable_module: true

  # Your foreman server address
  :host: 'https://localhost/'

  # Credentials. You'll be asked for them interactively if you leave them blank here
  :username: 'admin'
  #:password: 'example'

  # Check API documentation cache status on each request
  #:refresh_cache: false

  # API request timeout. Set to -1 for no timeout
  #:request_timeout: 120 #seconds

  # Follow API redirects. One of :never, :default, :always
  # Value :default means RestClient default behaviour - follow only in GET and HEAD requests
  #:follow_redirects: :never

When the user took that file and used it as a template for their ~/.hammer/cli.modules.d/foreman.yml, they'd end up with:

# cat ~/.hammer/cli.modules.d/foreman.yml
:foreman:
  # Enable/disable foreman commands
  :enable_module: true

  # Your foreman server address
  :host: 'https://localhost/'

  # Credentials. You'll be asked for them interactively if you leave them blank here
  :username: 'admin'
  :password: 'changeme'

(or similar)

Now in 6.3, hammer started to verify the SSL certificate, and the global config is regenerated properly by the installer:

# cat /etc/hammer/cli.modules.d/foreman.yml 
:foreman:
  # Enable/disable foreman commands
  :enable_module: true

  # Your foreman server address
  :host: 'https://sat-6-2-qa-rhel7.kangae.example.com'

:ssl:
  :ssl_ca_file: '/etc/pki/katello/certs/katello-server-ca.crt'

However, due to the fact that the user has `:host: 'https://localhost/'` in their ~/.hammer, this takes precedence and every hammer call fails.

foreman-maintain also generates an own config, based on the one in ~/.hammer:

# cat /etc/foreman-maintain/foreman-maintain-hammer.yml
---
:foreman:
  :enable_module: true
  :host: https://localhost/
  :username: admin
  :password: changeme

So to make f-maintain work, both files need to drop the `:host:` entry.

As a user, I think I'd like f-maintain to:
1. check my ~/.hammer/cli.modules.d/foreman.yml and warn me if it has anything else than $(hostname -f) for host
2. only copy username and password to /etc/foreman-maintain/foreman-maintain-hammer.yml (like it is done in the case there is no config in ~/.hammer and the user is asked)


Version-Release number of selected component (if applicable):
rubygem-foreman_maintain-0.1.3-1.el7sat.noarch

How reproducible:
100%

Steps to Reproduce:
1. have ":host: 'https://localhost/'" in ~/.hammer/cli.modules.d/foreman.yml
2. foreman-maintain upgrade run --target-version 6.3

Actual results:
Running Checks after upgrading to Satellite 6.3
================================================================================
Check for paused tasks:                                               [OK]
--------------------------------------------------------------------------------
Check whether all services are running using hammer ping:             [FAIL]
SSL error: hostname "localhost" does not match the server certificate
--------------------------------------------------------------------------------


Expected results:
Upgrade continues because "hammer ping" worked fine.

Additional info: