Sync latest openstack-common.

This fixes an issue when trying to run install_venv from within
the source directory.

Change-Id: Id4dcb070319ec52d0a1b466e911fbfdf805db613

tools/install_venv_common.py

@@ -25,6 +25,13 @@ import os
 import subprocess
 import sys
 
+
+possible_topdir = os.getcwd()
+if os.path.exists(os.path.join(possible_topdir, "openstackclient",
+                               "__init__.py")):
+    sys.path.insert(0, possible_topdir)
+
+
 from openstackclient.openstack.common import cfg