Incorrect error message is displayed when the user deletes a term which is in use on a license

Overview:

When the user tries to delete a Term which has been applied to a license the error message "There was an error deleting term [term_name]: org.hibernate.exception.ConstraintViolationException: could not execute statement" is displayed.

Steps to Reproduce:

1. Log into snapshot as diku_admin.
2. In the license app, Edit a license.
3. Apply a term and Save the license.
4. Open the Settings app and go to Licenses > Terms,
5. Locate the term applied in step 3 and select "Delete",
6. Confirm the deletion (select the "Delete" button in the "Delete term" modal").

Expected Results:

A dismissable callout should be displayed with the text "Error: Term [term name] was not deleted because it is in use on one or more licenses or amendments." as shown in the mockup.

Actual Results:

A dismissable callout is displayed with the error message "There was an error deleting term [term_name]: org.hibernate.exception.ConstraintViolationException: could not execute statement"

Additional info

The same error is displayed when the term is applied to an Amendment rather than a license.