Clarify gunicorn_status initialisation error

[Gu1nness]

When getting the master and workers PID , if it fails it is unclear whether it is the master PID or the workers PID that the plugin failed to get.
I hereby offer to clarify this if you think it is useful.

[sumpfralle]

Any help is appreciated!

This contrib repository is supposed to be the obvious place where people look for (and contribute) plugins. Due to the number of plugins (~1100) these are not really developed by the repository maintainers (including myself), but usually contributed and improved by the interested people, that really use these plugins. Whenever you stumble upon some nasty detail or an opportunity for improvement in one of the plugins you are using: go ahead and improve it for yourself and your fellow munin users.

Thank you for your time and your contribution!

[Gu1nness]

OK, I'll do this as well.

[github-actions]

Stale issue message