register might not succeed at first boot and procd will kill openwisp_config

[nemesifier]

register might not succeed at first boot because the network is not configured yet. In that case the agent will keep crashing and after 6 attempts procd will kill the agent.

It might be an acceptable solution to expect a possible failure, start a loop, check if the network is up: if it's up it will try to register, if not it will wait a bit before trying again.