Notify users when their password / API token no longer work

[zionyx]

As a user, it would be nice if Jenkins Tray is able to notify me that my password / API token no longer works. Sometimes i am forced to change my password due to corporate password policy that i have forgotten, or when the jenkins server changed its authentication method.

Without this tip / help, it would take some time before the I realize why the project turns grey on Jenkins Tray.

A dialog box that says something like, "Your password / API token for XXX Server(Jenkins URL) no longer work. Please update."