Use a lock for the catalog zones during dns__catz_zones_merge() to
avoid races between 'catz' and 'parentcatz'.
(cherry picked from commit 2ae3bc6e1d)
Use a lock for the catalog zones during dns__catz_zones_merge() to
avoid races between 'catz' and 'parentcatz'.
(cherry picked from commit 2ae3bc6e1d)