Acknowlege git.o.o as OpenStack's git server

OpenStack's cannonical git server is at git.o.o this patch
updates the index.rst to reflect that.

Change-Id: I54eeea7fab2e0f64ca9f23f7c328e2ff19721a41

Author: Anita Kuno

doc/source/index.rst

@@ -21,19 +21,19 @@ Getting Started
 
 * Check out `the wiki`_
 * Try `some commands`_
-* Read the source `on GitHub`_
+* Read the source `on OpenStack's Git server`_
 
 .. _the wiki: https://wiki.openstack.org/OpenStackClient
 .. _some commands: https://wiki.openstack.org/OpenStackClient/Commands
 
 Contributing
 ============
 
-Code is hosted `on GitHub`_. Submit bugs to the python-openstackclient project
-on  `Launchpad`_. Submit code to the openstack/python-openstackclient project
-using `Gerrit`_.
+Code is hosted `on OpenStack's Git server`_. Submit bugs to the
+python-openstackclient project on `Launchpad`_. Submit code to
+the openstack/python-openstackclient project using `Gerrit`_.
 
-.. _on GitHub: https://github.com/openstack/python-openstackclient
+.. _on OpenStack's Git server: https://git.openstack.org/cgit/openstack/python-openstackclient/tree
 .. _Launchpad: https://launchpad.net/python-openstackclient
 .. _Gerrit: http://wiki.openstack.org/GerritWorkflow