Relax default strict option under python3.x for configparser

Looks like things changed in 3.2:
"In previous versions of configparser behaviour matched strict=False."
from:
https://docs.python.org/3/library/configparser.html

Closes-Bug: #1652157

Change-Id: Iffb058b72b14b7535c501d5bf03b8f3576443b34

oslo_rootwrap/tests/test_rootwrap.py

@@ -44,6 +44,18 @@ class RootwrapLoaderTestCase(testtools.TestCase):
             self.assertEqual(["/fake/privsep-helper", "--context", "foo"],
                              filtermatch.get_command(privsep))
 
+    def test_strict_switched_off_in_configparser(self):
+        temp_dir = self.useFixture(fixtures.TempDir()).path
+        temp_file = os.path.join(temp_dir, 'test.conf')
+        f = open(temp_file, 'w')
+        f.write("""[Filters]
+privsep: PathFilter, privsep-helper, root
+privsep: PathFilter, privsep-helper, root
+""")
+        f.close()
+        filterlist = wrapper.load_filters([temp_dir])
+        self.assertIsNotNone(filterlist)
+
 
 class RootwrapTestCase(testtools.TestCase):
     if os.path.exists('/sbin/ip'):

oslo_rootwrap/wrapper.py

@@ -19,6 +19,7 @@ import os
 import pwd
 import signal
 
+import six
 from six import moves
 
 from oslo_rootwrap import filters
@@ -116,7 +117,8 @@ def load_filters(filters_path):
             continue
         for filterfile in filter(lambda f: not f.startswith('.'),
                                  os.listdir(filterdir)):
-            filterconfig = moves.configparser.RawConfigParser()
+            kwargs = {"strict": False} if six.PY3 else {}
+            filterconfig = moves.configparser.RawConfigParser(**kwargs)
             filterconfig.read(os.path.join(filterdir, filterfile))
             for (name, value) in filterconfig.items("Filters"):
                 filterdefinition = [s.strip() for s in value.split(',')]