net: sockets: tls: Mark accepted socket correctly in accept()

The TCP code expects that we know when the socket has called accept()
in order to continue connection attempt.

Fixes #21335

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

subsys/net/lib/sockets/sockets_tls.c

@@ -1297,6 +1297,8 @@ int ztls_accept_ctx(struct net_context *parent, struct sockaddr *addr,
 		}
 	}
 
+	net_context_set_accepting(child, false);
+
 	z_finalize_fd(
 		fd, child, (const struct fd_op_vtable *)&tls_sock_fd_op_vtable);