Fixed mitogen.yml (#8508)

Fixed the problem when call ansible-playbook contrib/mitogen/mitogen.yml
"The error was: 'dict object' has no attribute 'section'"

What type of PR is this?

/kind bug

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?: