Ignore pep8 E123.

From the pep8 spec:

  The closing brace/bracket/parenthesis on multi-line constructs
  may either line up under the last item of the list, as in:
  ...
  or it may be lined up under the first character of the line that
  starts the multi-line construct, as in:
  ...

Bizzarly, the pep8 tool ignores the first option.

Change-Id: Ic0e8f8ad964881276d213ffd50deb75a537c250b
Reviewed-on: https://review.openstack.org/28609
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins