blank trustedhosts #4

I ran into some annoyance with RemoteUserJiraAuth.properties
The comment says "Leave blank to allow all hosts." and shows
#trustedhosts=
as example. However
trustedhosts=
in the properties file wont work, because you only check if trustedhosts is not set, not if it is set to an empty value (at least that seems to be the problem I ran in).
Quickest would be to change the doc to "Don't set to allow all hosts." and remove
#trustedhosts=

Thank you very much for this very handy plugin.