main: Stop http server
main: Stop http server

Currently it's not stopped at all, so calling a REST request shutdown-time
may crash things at random places.

Fixes: #5702

But it's not the end of the story. Since the server stays up while we are
shutting things down, each subsystem should carefully handle the cases when
it's half-down, but a request comes. A better solution is to unregister
rest verbs eventually, but httpd's rules cannot do it now.

Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@scylladb.com>

scylladb/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla