The RPCClient class has a reraise_exceptions list containing exception types
that should be reraised client side instead of wrapping them in a RemoteException
instance.
If the remote exception comes with a 404 HTTP status code, it was automatically
raised as a RemoteException regardless if the exception type must be reraised
client side.
So ensure to not raise a RemoteException if the 404 remote exception should
be reraised.
That change is required to fix HTTP status code for missing objects when querying
the swh-objstorage RPC endpoints (aka 404, see D8228).