SA14: Adjust `rewrite_update` parameter mangling
SA14: Adjust `rewrite_update` parameter mangling

This patch resembles the missing bits, where previously things have not been
in order. It is about the correct wrapping/unwrapping of data returned to and
from `rewrite_update`, which deviates between SA < 1.4 an SA >= 1.4.

crate/crate-python,crate/crate-python