removed duplicated code, using pydal's _compat.py

gluon/settings.py

@@ -10,7 +10,7 @@ import os
 import sys
 import platform
 from gluon.storage import Storage
-from gluon._compat import PY2
+from pydal._compat import PY2
 
 global_settings = Storage()
 settings = global_settings  # legacy compatibility