replace manual home dir with config option

modules/mail/himalaya.nix

@@ -68,7 +68,7 @@
             mu.enable = false;
             notmuch.enable = false;
             passwordCommand =
-              "${pkgs.age}/bin/age --decrypt --identity /home/${config.user}/.ssh/id_ed25519 ${
+              "${pkgs.age}/bin/age --decrypt --identity ${config.homePath}/.ssh/id_ed25519 ${
                 builtins.toString ./mailpass.age
               }";
             smtp = {