maintainers: update pongo1231's email

maintainers/maintainer-list.nix

···
     name = "Pedro Pombeiro";
   };
   pongo1231 = {
-    email = "[e-mail]";
+    email = "[e-mail]";
     github = "pongo1231";
     githubId = 4201956;
     name = "pongo1231";