net: lwm2m: Fix LwM2M resume from Update registration state

If LwM2M engine was paused at ENGINE_UPDATE_SENT it was not
able to resume lwm2m engine properly. There was also missing
RD client Pending message free which could also affect a issue.

Signed-off-by: Juha Heiskanen <juha.heiskanen@nordicsemi.no>
1 file changed