icinga2: Add pname to .vim

Makes it compatible with the vim module of home-manager which expects
pname to be set.

pkgs/servers/monitoring/icinga2/default.nix

@@ -82,7 +82,7 @@ stdenv.mkDerivation rec {
     ''}
   '';
 
-  vim = runCommand "vim-icinga2-${version}" {} ''
+  vim = runCommand "vim-icinga2-${version}" { pname = "vim-icinga2"; } ''
     mkdir -p $out/share/vim-plugins
     cp -r "${src}/tools/syntax/vim" $out/share/vim-plugins/icinga2
   '';