coturn service: Fix coturn to properly come up (#29415)

properly also in case dhcpcd being used.

Without network-online.target, coturn will fail to listen on addresses that
come up with dhcpcd.

Changed files
+2 -1
nixos
modules
services
networking
+2 -1
nixos/modules/services/networking/coturn.nix
···
systemd.services.coturn = {
description = "coturn TURN server";
-
after = [ "network.target" ];
wantedBy = [ "multi-user.target" ];
unitConfig = {
···
systemd.services.coturn = {
description = "coturn TURN server";
+
after = [ "network-online.target" ];
+
wants = [ "network-online.target" ];
wantedBy = [ "multi-user.target" ];
unitConfig = {