Comment 1 for bug 1866106

This looks valid to me. When someone tries to set None in the config file, the StrOpt appears to be unable to treat it as anything other than a string. So the true None will not match the string 'None'.

I see several other examples under nova/conf/ especially in nova/conf/libvirt.py where a None choice is represented as 'none' likely for this reason.

We will need to change the current None choice to be 'none' and handle it accordingly in the code.