Remove NRF dependency from SMF
SMF will retry the NF registration and the UPF subscription if the NRF is not ready yet.
SMF send the UPF subscription before the own http server is up and running, so the NRF is not able to answer immediately. I quick-fixed it with a sleep. @defosseu it should resolve nrf issue 4.
@arora It should remove the nrf dependency from smf, I made some manual tests, but please test it as well. I will continue removing the dependencies from the other NFs.