(maint) Fix the 'nothing to manage' message.

In the refactoring for #23081, in commit 6ff0a103, the message
"Nothing to manage; no ensure and the resource doesn't exist"
was introduced.  However, this message would spuriously fire
if the resource was in fact managed by an ensure property, e.g.

rm -rf /tmp/foo; be puppet apply -e 'file {"/tmp/foo": ensure => present}' --debug

This patch corrects that spurious debug message.