rspamd: use package from upstream NixOS service

mail-server/rspamd.nix

@@ -27,6 +27,7 @@ let
   postfixCfg = config.services.postfix;
   rspamdCfg = config.services.rspamd;
 
+  rspamdPkg = config.services.rspamd.package;
   rspamdUser = config.services.rspamd.user;
   rspamdGroup = config.services.rspamd.group;
 
@@ -45,7 +46,7 @@ let
     pkgs.writeShellScript "dkim-keygen-${domain}-${selector}" ''
       if [ ! -f "${privkey}" ]
       then
-        ${lib.getExe' pkgs.rspamd "rspamadm"} dkim_keygen ${
+        ${lib.getExe' rspamdPkg "rspamadm"} dkim_keygen ${
           lib.cli.toCommandLineShellGNU { } {
             inherit
               domain
@@ -114,7 +115,7 @@ in
           nativeBuildInputs = with pkgs; [ makeWrapper ];
         }
         ''
-          makeWrapper ${pkgs.rspamd}/bin/rspamc $out/bin/rspamc \
+          makeWrapper ${lib.getExe' rspamdPkg "rspamc"} $out/bin/rspamc \
             --add-flags "-h /run/rspamd/worker-controller.sock"
         ''
       )
@@ -288,7 +289,7 @@ in
       # default behaviour when called without a date.
       # https://github.com/rspamd/rspamd/issues/4062
       script = toString [
-        (lib.getExe' pkgs.rspamd "rspamadm")
+        (lib.getExe' rspamdPkg "rspamadm")
         "dmarc_report"
         "$(date -d 'yesterday' '+%Y%m%d')"
       ];