Use LogRecord.msg instead of LogRecord.message in tests
Use LogRecord.msg instead of LogRecord.message in tests

From the docs for LogRecord.message [1],

> This is set when Formatter.format() is invoked.

Apparently we may find ourselves in a situation [2] where that never
happens? Really weird that it failed *midway* through the test though;
maybe some concurrent test removed all formatters?

ERROR: test_known_bad_ec_config
(test.unit.common.test_storage_policy.TestStoragePolicies)
----------------------------------------------------------------------
Traceback (most recent call last):
  File ".../mock/mock.py", line 1305, in patched
    return func(*args, **keywargs)
  File ".../test/unit/common/test_storage_policy.py", line 688, in test_known_bad_ec_config
    self.assertIn(msg, records[0].message)
AttributeError: 'LogRecord' object has no attribute 'message'

[1] https://docs.python.org/2/library/logging.html#logrecord-attributes
[2] http://logs.openstack.org/59/460359/1/check/gate-swift-tox-xfs-tmp-py27-ubuntu-xenial/5ecc2cb/console.html#_2017-04-27_01_06_43_346096
Change-Id: I8f5ac0ec1195a233f14edc0126de1d1cea7a6e2f

clayg/swift,psachin/swift,matthewoliver/swift,psachin/swift,clayg/swift,smerritt/swift,matthewoliver/swift,swiftstack/swift,openstack/swift,notmyname/swift,smerritt/swift,notmyname/swift,matthewoliver/swift,psachin/swift,tipabu/swift,smerritt/swift,matthewoliver/swift,clayg/swift,swiftstack/swift,openstack/swift,openstack/swift,smerritt/swift,nadeemsyed/swift,nadeemsyed/swift,swiftstack/swift,tipabu/swift,redbo/swift,redbo/swift,notmyname/swift,nadeemsyed/swift,openstack/swift,tipabu/swift,psachin/swift,tipabu/swift,nadeemsyed/swift,clayg/swift,notmyname/swift