Exception logging fails if system locale differs from en_us

[Timofey Durakov]

oslo_db.sqlalchemy.provision.Backend._ensure_backend_available throws exception:
      File "/home/tdurakov/nova/.tox/py27/local/lib/python2.7/site-packages/oslo_db/sqlalchemy/test_base.py", line 58, in setUp
        self.provision = provision.ProvisionedDatabase(self.DRIVER)
      File "/home/tdurakov/nova/.tox/py27/local/lib/python2.7/site-packages/oslo_db/sqlalchemy/provision.py", line 53, in __init__
        self.backend = Backend.backend_for_database_type(database_type)
      File "/home/tdurakov/nova/.tox/py27/local/lib/python2.7/site-packages/oslo_db/sqlalchemy/provision.py", line 103, in backend_for_database_type
        return backend._verify()
      File "/home/tdurakov/nova/.tox/py27/local/lib/python2.7/site-packages/oslo_db/sqlalchemy/provision.py", line 130, in _verify
        eng = self._ensure_backend_available(self.url)
      File "/home/tdurakov/nova/.tox/py27/local/lib/python2.7/site-packages/oslo_db/sqlalchemy/provision.py", line 163, in _ensure_backend_available
        dict(dbapi=url.drivername, err=d_e)
      File "/usr/lib/python2.7/logging/__init__.py", line 1152, in info
        self._log(INFO, msg, args, **kwargs)
      File "/usr/lib/python2.7/logging/__init__.py", line 1271, in _log
        self.handle(record)
      File "/usr/lib/python2.7/logging/__init__.py", line 1281, in handle
        self.callHandlers(record)
      File "/usr/lib/python2.7/logging/__init__.py", line 1321, in callHandlers
        hdlr.handle(record)
      File "/usr/lib/python2.7/logging/__init__.py", line 749, in handle
        self.emit(record)
      File "/usr/lib/python2.7/logging/__init__.py", line 879, in emit
        self.handleError(record)
      File "/usr/lib/python2.7/logging/__init__.py", line 851, in emit
        msg = self.format(record)
      File "/usr/lib/python2.7/logging/__init__.py", line 724, in format
        return fmt.format(record)
      File "/usr/lib/python2.7/logging/__init__.py", line 464, in format
        record.message = record.getMessage()
      File "/usr/lib/python2.7/logging/__init__.py", line 328, in getMessage
        msg = msg % self.args
    UnicodeDecodeError: 'ascii' codec can't decode byte 0xd0 in position 19: ordinal not in range(128)

There is postgres db instance on machine, localized with ru_ru. No openstack_citest user in DB was created.
eng.connect method call fails with localized error:
(OperationalError) ВАЖНО: пользователь "openstack_citest" не прошёл проверку подлинности (по паролю)
ВАЖНО: пользователь "openstack_citest" не прошёл проверку подлинности (по паролю)
 None None
logging such localized error fails in except section