Warning when Network Manager is not active

[marcogracklauer]

We are currently roll out this module for our environment which is mostly RHEL 8 and 9 .
We still have a few RHEL7-Systems in Extended Support with network manager deactived.

Unfortunately we always get a warning because the fact cannot be gathered.

/usr/bin/nmcli -t -m multiline general status' returned 8: Error: NetworkManager is not running.

Would it be possible to add a check if network manager is active in lib/facter/simplib__networkmanager.rb to prevent this warning?