Allow using RetryableJobError

[yelizariev]

built-in safe_eval transforms original exception into ValueError.
We need to implement opposite transformation somewhere here:

sync-addons/sync/models/sync_task.py

Line 135 in ab94a2f

result = self._eval(code, function, args, kwargs, eval_context)

Originally posted by @yelizariev in #339 (comment)