Remove executable bit on some files

Caught by:

nose.selector: INFO: /opt/stack/new/tempest/tempest/services/identity/v3/json/endpoints_client.py is executable; skipped
nose.selector: INFO: /opt/stack/new/tempest/tempest/services/identity/v3/xml/endpoints_client.py is executable; skipped

Change-Id: If3b3abe9aebff682d2725c6047e056df1a5ffe5b
Signed-off-by: Julien Danjou <julien@danjou.info>
Merge "Remove executable bit on some files"