Disable copy option for run-times

Current Situation

• A "Copy" option is available for <run_time> elements like "Any Weekday", "Days in a Month", etc.
• A "Copy" option is available for groups within the elements "Any Weekday", "Days in a Month", etc.
• After copying&pasting a <run_time> element and when trying to delete it, JOE throws an error (see attached file)

Error reproduction

• A group is created under any element of a <run_time>, for instance "Any Weekday".
• In order to create another group, the user uses the existing group and copies the group (by a right click on the mouse) and pastes the group this under "Any Weekday".
• Now the "Delete" option for the group (by a right click on the mouse) is available and JOE throws the error meant above.

Desired Behavior

• The option for the elements "Any Weekday", "Days in a Month" etc. should be disabled.