Time conditions bug - switching from time group mode to calendar mode still keeps time group tied to the time condition

Steps to reproduce:

1. edit a time condition that is currently set to TIME GROUP MODE, and has a time group SELECTED (must click submit then apply changes)
2. Click on CALENDAR MODE
3. submit and apply changes
4. try to delete the time group and it will tell you that it is still in use and can’t be deleted.
   In order to delete it, you have to go back in to edit the time condition, click on TIME GROUP MODE, and from the Time Group dropdown you have to click “–Select a Group” and then click on CALENDAR MODE again, click submit and then you will be able to delete that time group.

Expected functionality:
When you change a time condition to use calendar mode instead of time group mode, it should allow you to delete that time group since logically it’s no longer in use as the time condition is using calendar mode. It’s unlogical for the user to have to change the time group’s dropdown to Select a Group for it to unlink the time group. Normally in other applications once you select another mode, the original mode is unlinked.