samba: remove redundant dependency on network.target

This reverts commit 679d5e8bd5.
Services samba-smbd, samba-nmbd and samba-winbind are part of
samba.target, which already has an After=network.target

nixos/modules/services/network-filesystems/samba.nix

@@ -40,7 +40,6 @@ let
   daemonService = appName: args:
     { description = "Samba Service Daemon ${appName}";
 
-      after = [ "network.target" ];
       requiredBy = [ "samba.target" ];
       partOf = [ "samba.target" ];