If you wanted to shut the code up without changing the default behavior, you could simply import the following .reg file:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\OpenVPN]
"ovpn_admin_group"="OpenVPN Administrators"
Please note that,
if the default name
ever changes your setup will suddenly use the (then) non-default group name "OpenVPN Administrators".