Revert "Revert "component/proftpd: use slapos.cookbook:userinfo""

This reverts commit 9715449d.

component/proftpd/buildout.cfg

@@ -4,12 +4,8 @@ extends =
   ../openssl/buildout.cfg
   ../zlib/buildout.cfg
 
-[proftpd-environment]
-recipe = collective.recipe.environment
-# This component depends on https://nexedi.erp5.net/bug_module/20180402-716ACB/ being fixed
-
-[proftpd-grp]
-recipe = collective.recipe.grp
+[proftpd-userinfo]
+recipe = slapos.cookbook:userinfo
 
 [proftpd]
 recipe = slapos.recipe.cmmi
@@ -24,8 +20,8 @@ configure-options =
 environment = 
   CPPFLAGS=-I${zlib:location}/include -I${openssl:location}/include
   LDFLAGS=-L${zlib:location}/lib -Wl,-rpath=${zlib:location}/lib -L${openssl:location}/lib -Wl,-rpath=${openssl:location}/lib
-  install_user=${proftpd-environment:USER}
-  install_group=${proftpd-grp:GROUP}
+  install_user=${proftpd-userinfo:pw-name}
+  install_group=${proftpd-userinfo:gr-name}
 
 
 [ftpasswd]