Add CONFIG_SITE environment variable to blacklist.

This variable is used by ./configure to guess libdir name (lib, lib64, ...). Of course we just want 'lib' to be chosen.

slapos/grid/utils.py

@@ -62,6 +62,7 @@ SYSTEM_ENVIRONMENT_REMOVE_LIST = [
   'TMP',
   'TMPDIR',
   'USER',
+  'CONFIG_SITE',
 ]
 
 LOCALE_ENVIRONEMNT_REMOVE_LIST = [