enableHost.php and disableHost.php must return true or false:
- They should return a command output element to show in
  console.
8. Create disableHost.php file.
- It receives hostname.
- Exejute a2dissite.
- If its port is useless, remove the listen directive of its
  port.
- Returns (json):
  - 'return' -> true on success, false otherwise.
  - 'message' -> The static information text.
  - 'command_output' ->
    - 'return' -> The value that a2ensite returns.
    - 'message' -> stderr and stdin printed by a2ensite.
Show host list properly:
- Show properly the default virtual host
  (a2ensite -> 000-default).
- Hide files whose filename ends with ‘.backup’ or ‘~’.