fix util.set_owner_process

Python 2.x is not supported anymore, let's remove this extra feature.

fix #3212

Author: benoitc

Diff for: gunicorn/util.py

@@ -147,10 +147,6 @@ def set_owner_process(uid, gid, initgroups=False):
             except KeyError:
                 initgroups = False
 
-        # versions of python < 2.6.2 don't manage unsigned int for
-        # groups like on osx or fedora
-        gid = abs(gid) & 0x7FFFFFFF
-
         if initgroups:
             os.initgroups(username, gid)
         elif gid != os.getgid():