POSTing to /election/:id/audit/reset breaks things

[MorganLove]

Currently on master after POSTing to /election/:id/audit/reset further calls to endpoints using that id result in 500 errors.

ERROR in app: Exception on /election/9710b544-8fb1-474f-ac50-97d8b8505be5/audit/status [GET]
Traceback (most recent call last):
  File "/Users/morgan/.local/share/virtualenvs/arlo-cgZpGxiy/lib/python3.7/site-packages/flask/app.py", line 2311, in wsgi_app
    response = self.full_dispatch_request()
  File "/Users/morgan/.local/share/virtualenvs/arlo-cgZpGxiy/lib/python3.7/site-packages/flask/app.py", line 1834, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Users/morgan/.local/share/virtualenvs/arlo-cgZpGxiy/lib/python3.7/site-packages/flask/app.py", line 1737, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/Users/morgan/.local/share/virtualenvs/arlo-cgZpGxiy/lib/python3.7/site-packages/flask/_compat.py", line 36, in reraise
    raise value
  File "/Users/morgan/.local/share/virtualenvs/arlo-cgZpGxiy/lib/python3.7/site-packages/flask/app.py", line 1832, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Users/morgan/.local/share/virtualenvs/arlo-cgZpGxiy/lib/python3.7/site-packages/flask/app.py", line 1818, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/Users/morgan/Desktop/votingworks/arlo/app.py", line 207, in audit_status
    election = get_election(election_id)
  File "/Users/morgan/Desktop/votingworks/arlo/app.py", line 44, in get_election
    return Election.query.filter_by(id = (election_id or '1')).one()
  File "/Users/morgan/.local/share/virtualenvs/arlo-cgZpGxiy/lib/python3.7/site-packages/sqlalchemy/orm/query.py", line 3289, in one
    raise orm_exc.NoResultFound("No row was found for one()")
sqlalchemy.orm.exc.NoResultFound: No row was found for one()

[benadida]

fixed.