Requirements containing non-ascii characters causes internal error

Updating a lease with requirements including non-ascii characters caused the following trace:

2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server [-] Exception during message handling
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server Traceback (most recent call last):
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/server.py", line 155, in _process_incoming
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server res = self.dispatcher.dispatch(message)
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 222, in dispatch
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server return self._do_dispatch(endpoint, method, ctxt, args)
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 192, in _do_dispatch
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server result = func(ctxt, **new_args)
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/blazar/utils/service.py", line 77, in run_method
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server return method(**kwargs)
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/blazar/status.py", line 223, in wrapper
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server lease_id, str(e))
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server UnicodeEncodeError: 'ascii' codec can't encode character u'\u201c' in position 50: ordinal not in range(128)
2018-11-12 13:38:25.827 184217 ERROR oslo_messaging.rpc.server
2018-11-12 13:38:25.834 184189 ERROR blazar.api.v1.utils [-] Request aborted with status code 500 and message 'Internal Server Error'
2018-11-12 13:38:25.858 184189 ERROR blazar.api.v1.utils [-] Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/blazar/api/v1/utils.py", line 76, in handler
    return func(**kwargs)
  File "/usr/lib/python2.7/site-packages/blazar/api/v1/validation.py", line 53, in handler
    return func(*args, **kwargs)
  File "/usr/lib/python2.7/site-packages/blazar/api/v1/leases/v1_0.py", line 54, in leases_update
    return api_utils.render(lease=_api.update_lease(lease_id, data))
  File "/usr/lib/python2.7/site-packages/blazar/utils/__init__.py", line 32, in __run_method
    return getattr(self.instance, __name)(*args, **kwargs)
  File "/usr/lib/python2.7/site-packages/blazar/policy.py", line 110, in wrapped
    return func(self, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/blazar/api/v1/leases/service.py", line 76, in update_lease
    return self.manager_rpcapi.update_lease(lease_id, data)
  File "/usr/lib/python2.7/site-packages/blazar/manager/leases/rpcapi.py", line 43, in update_lease
    return self.call('update_lease', lease_id=lease_id, values=values)
  File "/usr/lib/python2.7/site-packages/blazar/utils/service.py", line 44, in call
    return self._client.call(ctx.to_dict(), name, **kwargs)
  File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/client.py", line 465, in call
    return self.prepare().call(ctxt, method, **kwargs)
  File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/client.py", line 169, in call
    retry=self.retry)
  File "/usr/lib/python2.7/site-packages/oslo_messaging/transport.py", line 97, in _send
    timeout=timeout, retry=retry)
  File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 566, in send
    retry=retry)
  File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 557, in _send
    raise result
RemoteError: Remote error: UnicodeEncodeError 'ascii' codec can't encode character u'\u201c' in position 50: ordinal not in range(128)

Lease stayed in UPDATING status.

This happened on a customized code base: first verify if this is repeatable with upstream code.