Notification View should store assigned Job Ressource in MailFragment

Current Situation

When assigning a job resource JR1 to a mail fragment in the notification view, the resource JR1 is stored and also the the resource eMailDefault is stored.

<MailFragment name="mail_on_failure" job_resources="eMailDefault,notification"

Desired Behavior

Only the assigned job ressource(s) should be stored when deploying the configuration for notifications. A user can assign more than one job resource.