[BUGFIX] Throw 404 exception when updating a non-existing resource
Specifying a non-existing identity when converting a persistent
object using the ``PersistentObjectConverter`` the ``PropertyMapper``
tries to apply conversions on the ``TargetNotFoundError`` instead of
returning the error directly.
The reason for this regression is the new ``TargetNotFoundError`` that
has been introduced with I5231ccddaef1a6b49e62bb29bdd3ff99dc2bb994 in
order to be able to handle that case more gracefully. Previously an
exception was thrown directly.
Releases: master, 3.0