fix logic in NvpApiException

[Sean McCully]

ERROR: neutron.tests.unit.nicira.test_nvplib.TestNvplibLogicalRouters.test_update_lrouter_port_ips_nvp_exception_raises
----------------------------------------------------------------------
_StringException: Empty attachments:
  pythonlogging:''

Traceback (most recent call last):
  File "/home/smccully/projects/launchpad-workflow/neutron/neutron/tests/unit/nicira/test_nvplib.py", line 884, in test_update_lrouter_port_ips_nvp_exception_raises
    lrouter_port['uuid'], [], [])
  File "/usr/lib/python2.7/site-packages/testtools/testcase.py", line 394, in assertRaises
    self.assertThat(our_callable, matcher)
  File "/usr/lib/python2.7/site-packages/testtools/testcase.py", line 406, in assertThat
    mismatch = matcher.match(matchee)
  File "/usr/lib/python2.7/site-packages/testtools/matchers/_exception.py", line 99, in match
    mismatch = self.exception_matcher.match(exc_info)
  File "/usr/lib/python2.7/site-packages/testtools/matchers/_higherorder.py", line 61, in match
    mismatch = matcher.match(matchee)
  File "/usr/lib/python2.7/site-packages/testtools/testcase.py", line 386, in match
    reraise(*matchee)
  File "/usr/lib/python2.7/site-packages/testtools/matchers/_exception.py", line 92, in match
    result = matchee()
  File "/usr/lib/python2.7/site-packages/testtools/testcase.py", line 867, in __call__
    return self._callable_object(*self._args, **self._kwargs)
  File "/home/smccully/projects/launchpad-workflow/neutron/neutron/plugins/nicira/nvplib.py", line 1343, in update_lrouter_port_ips
    "router logical port:%s") % str(e)
TypeError: __str__ returned non-string (type Message)

This is sometimes failing and sometimes not!!!!!

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/47769

[Sean McCully (sean-mccully)]

This appears related,

ERROR: neutron.tests.unit.nicira.test_nvplib.TestNvplibSecurityProfile.test_delete_non_existing_securityprofile_raises
----------------------------------------------------------------------
_StringException: Empty attachments:
  pythonlogging:''

Traceback (most recent call last):
  File "/home/smccully/projects/launchpad-workflow/neutron/neutron/tests/unit/nicira/test_nvplib.py", line 1211, in test_delete_non_existing_securityprofile_raises
    self.fake_cluster, 'whatever')
  File "/usr/lib/python2.7/site-packages/testtools/testcase.py", line 394, in assertRaises
    self.assertThat(our_callable, matcher)
  File "/usr/lib/python2.7/site-packages/testtools/testcase.py", line 406, in assertThat
    mismatch = matcher.match(matchee)
  File "/usr/lib/python2.7/site-packages/testtools/matchers/_exception.py", line 99, in match
    mismatch = self.exception_matcher.match(exc_info)
  File "/usr/lib/python2.7/site-packages/testtools/matchers/_higherorder.py", line 61, in match
    mismatch = matcher.match(matchee)
  File "/usr/lib/python2.7/site-packages/testtools/testcase.py", line 386, in match
    reraise(*matchee)
  File "/usr/lib/python2.7/site-packages/testtools/matchers/_exception.py", line 92, in match
    result = matchee()
  File "/usr/lib/python2.7/site-packages/testtools/testcase.py", line 867, in __call__
    return self._callable_object(*self._args, **self._kwargs)
  File "/home/smccully/projects/launchpad-workflow/neutron/neutron/plugins/nicira/nvplib.py", line 1152, in delete_security_profile
    LOG.error(format_exception("Unknown", e, locals()))
  File "/home/smccully/projects/launchpad-workflow/neutron/neutron/plugins/nicira/nvplib.py", line 1047, in format_exception
    return ' '.join(msg)
TypeError: sequence item 0: expected string, Message found

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/81685