RetryRequest shouldn't log stack trace by default, or it should be configurable by the exception

I see the following littering the logs and it strikes me as wrong:

2018-12-18 01:01:46.259 34 DEBUG neutron.plugins.ml2.managers [req-196ce43f-2408-48f4-9c7e-bb90f66c9c14 - - - - -] DB exception raised by Mechanism driver 'opendaylight_v2' in update_port_precommit _call_on_drivers /usr/lib/python2.7/site-packages/neutron/plugins/ml2/managers.py:434
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers Traceback (most recent call last):
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers File "/usr/lib/python2.7/site-packages/neutron/plugins/ml2/managers.py", line 427, in _call_on_drivers
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers getattr(driver.obj, method_name)(context)
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers File "/usr/lib/python2.7/site-packages/oslo_log/helpers.py", line 67, in wrapper
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers return method(*args, **kwargs)
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers File "/usr/lib/python2.7/site-packages/networking_odl/ml2/mech_driver_v2.py", line 117, in update_port_precommit
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers context, odl_const.ODL_PORT, odl_const.ODL_UPDATE)
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers File "/usr/lib/python2.7/site-packages/networking_odl/ml2/mech_driver_v2.py", line 87, in _record_in_journal
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers ml2_context=context)
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers File "/usr/lib/python2.7/site-packages/networking_odl/journal/journal.py", line 123, in record
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers raise exception.RetryRequest(e)
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers RetryRequest
2018-12-18 01:01:46.259 34 ERROR neutron.plugins.ml2.managers

Since this is an explicit request by the operation to retry, and not some unexpected behavior, it shouldn't log the stack trace.
If you really want more fine grained control (over not logging the trace completely), a flag can be added to the exception to determine whether the log of it should contain the stack trace or not.

The code in question is here (also on master but this rocky url is simpler):
https://github.com/openstack/neutron/blob/stable/rocky/neutron/plugins/ml2/managers.py#L433