zmq invalid key

[jasongrout]

I saw this in the log:

Traceback (most recent call last):
  File "device_process.py", line 790, in <module>
    keys=keys, resource_limits=resource_limits)
  File "device_process.py", line 352, in device
    while not fs.create_secret(session=session):
  File "/padic/scratch/jason/simple-python-db-compute/db_zmq.py", line 35, in f
    output=self.socket.recv_pyobj()
  File "socket.pyx", line 705, in zmq.core.socket.Socket.recv_pyobj (zmq/core/socket.c:5903)
cPickle.UnpicklingError: invalid load key, '{'.

[jasongrout]

This looks like a duplicate of gh-237