main: Start the API service as the last step
main: Start the API service as the last step

This reverts commit f0d68e4 ("main: start the http server in the first
step"). The service layer is not ready to serve clients before it's
fully up and running which causes early startup crashes everywhere.
Message-Id: <d7477d9c90a6b8d72d7dcd3c6c12f242f2314732@scylladb.com>

duarten/scylla,avikivity/scylla,raphaelsc/scylla,avikivity/scylla,scylladb/scylla,raphaelsc/scylla,kjniemi/scylla,scylladb/scylla,kjniemi/scylla,duarten/scylla,scylladb/scylla,duarten/scylla,scylladb/scylla,kjniemi/scylla,avikivity/scylla,raphaelsc/scylla