* Fixes#18663. Bad handling of existing config in dellos9 module.
The dellos9 module doesn't build correctly the internal
structures used to represent the existing config of the managed
network device. This leads to apply changes every time the
playbook is run, even if the existing config is the same that the
one you are trying to push into the device.
Probably this problem exist also in the dellos6 and dellos10
modules, but I only fixed it in the dellos9 module.
The fix modifies two methods. The first one is `get_config`,
where the return clause didn't work correctly when the flow
doesn't enter in the `if` block. In that case the `contents`
variable is not an array an this should be handled.
The second fix is in the `get_sublevel_config` method. In this
case the indentation whitespaces of the parents should be rebuild
because further functions and methods required it to handle
correctly comparisons used to check if changes should be pushed
into device.
* Fixes#18663 for dellos10 module with the same patches as dellos9.
