Update links in README

Change the outdated links to the latest links in README.

Change-Id: Iba34d4713819f17d8f104e760861190a1139e556

README.rst

@@ -2,8 +2,8 @@
 Team and repository tags
 ========================
 
-.. image:: https://governance.openstack.org/badges/karbor.svg
-    :target: https://governance.openstack.org/reference/tags/index.html
+.. image:: https://governance.openstack.org/tc/badges/karbor.svg
+    :target: https://governance.openstack.org/tc/reference/tags/index.html
 
 .. Change things from this point on