Code review comment for ~guoqiao/charm-nrpe:LP1906991-chown-nagios-dirs

+1 to use the more pythonic os.chown
-1 to chown recursively: if permissions on files written by other charms are wrong, it's up to them to fix them

Also note Xav's comment[0]. I think using setgid is a good idea.

[0] https://bugs.launchpad.net/charm-hw-health/+bug/1906991/comments/2