Revert "Remove maintainership"

I'm baaaaack!

This patch reverts my patch where I removed myself as maintainer because
of my traveling. I'm back now and I want to maintain these packages
again.

This reverts commit ce1c1e3093.

pkgs/tools/misc/multitail/default.nix

@@ -21,7 +21,7 @@ stdenv.mkDerivation rec {
   meta = {
     homepage = http://www.vanheusden.com/multitail/;
     description = "tail on Steroids";
-    maintainers = with stdenv.lib.maintainers; [ ];
+    maintainers = with stdenv.lib.maintainers; [ matthiasbeyer ];
     platforms = stdenv.lib.platforms.unix;
     license = stdenv.lib.licenses.gpl2Plus;
   };