has a bug, it is not implementing the behavior described in https://github.com/jenkinsci/git-plugin/blob/master/src/main/java/hudson/plugins/git/extensions/GitSCMExtension.java#L58-L60
what should happen is, that the first extension that return true of false value is returned. only if the extension return null, other extensions should be check.
but what actually happens is, that if a extension returns true. it will loop thru the other extensions, instead of returning the actual value.
a possible fix for this, that fits the documented behavior could look like this:
please review and check.
i marked this as critical, since it prevents exclusions form functioning.