service: fix use-after-free on service data update

service: fix use-after-free on service data update

When updating runtime data for service already having previous data, the
call to service_data_trigger() will indirectly access the just freed
`s->data` memory through the `s->data_blob` AVL structure.

Fix this issue by moving the call to `service_data_trigger()` before the
freeing of `s->data`.

Signed-off-by: Jo-Philipp Wich <[email protected]>