remove the postmaster alias for myself

hosts/services/mail/default.nix

@@ -29,12 +29,12 @@ in {
         aliases = [
           "contact@irde.st"
           "info@irde.st"
+          "postmaster@irde.st"
         ];
       };
       "yuka@irde.st" = {
         hashedPassword = "$6$PoaHdbe72ypK$FCm/ZYj4aDcXkvJtbr8VP/.zX7INmpFmKOG7aPiLYvUf.EXZu03bROY2FP394/YMBpc.BBwY.5SOIMyH4bmLB1";
         aliases = [
-          "postmaster@irde.st"
         ];
       };
       "gitlab@irde.st".hashedPassword = "$6$IDEtwgV0$fBigESDDM2sewgvuH.wIekjJpT2kpfmMvAX4cohNRfwRHxDX/N3J0qAT56dffpxmbmboCRV/ZPgWugO3mejp90";