Switch last 2 files using /usr/bin/env to /usr/bin/python3

Other python scripts already use python3 by default. Both files don't have exec
bits so they have to be run using python interpret on command line anyway:

    $ python3 ./setup.py ...

Signed-off-by: Petr Lautrbach <plautrba@redhat.com>

libsemanage/src/pywrap-test.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python3
 from __future__ import print_function
 
 import sys

python/sepolicy/setup.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python3
 
 # Author: Thomas Liu <tliu@redhat.com>
 # Author: Dan Walsh <dwalsh@redhat.com>