maintainers: drop kroell

Single package addition in 2018, never came back.

maintainers/maintainer-list.nix

@@ -14073,12 +14073,6 @@
     name = "Kristoffer Longva Eriksen";
     matrix = "@krisleri:pvv.ntnu.no";
   };
-  kroell = {
-    email = "nixosmainter@makroell.de";
-    github = "rokk4";
-    githubId = 17659803;
-    name = "Matthias Axel Kröll";
-  };
   krostar = {
     email = "alexis.destrez@pm.me";
     github = "krostar";

pkgs/by-name/ss/ssocr/package.nix

@@ -30,7 +30,6 @@ stdenv.mkDerivation rec {
     description = "Seven Segment Optical Character Recognition";
     homepage = "https://github.com/auerswal/ssocr";
     license = licenses.gpl3;
-    maintainers = [ maintainers.kroell ];
     mainProgram = "ssocr";
     platforms = platforms.unix;
   };