ansible_ipa_server.py: Calm down ansible-test "metaclass-boilerplate"

ansible-test sanity test "metaclass-boilerplate" fails now to recognize
the line "__metaclass__ = type" if there is a pylint disable comment
appended to the same line to not fail on using bad class naming.

The pylint disable comment has been moved to an extra preceding line and
an additional enable commend has been added after the metaclass line.