Sanitize dim tasks during migration

[c8y3]

When retrieving a dim tasks (

iris-web/source/app/blueprints/pages/dim_tasks/dim_tasks.py

Line 63 in b3a36cd

except AttributeError:

) the code may catch an AttributeError exception. This seems to correspond to the case where a task, from a previous version of Iris, was stored in an old format in the database.
Can this still be a concern today?
Wouldn't it simplify the code, to sanitize tasks during specific database migration steps?