add upgrade note for exception message change in  libcloud/common/openstack_identity.py:691
add upgrade note for exception message change in  libcloud/common/openstack_identity.py:691

mistio/libcloud,Kami/libcloud,mistio/libcloud,Kami/libcloud,mistio/libcloud,apache/libcloud,Kami/libcloud,apache/libcloud,apache/libcloud