CI Flake `test_sendpay_grouping`

[ddustin]

FAILED tests/test_pay.py::test_sendpay_grouping - AssertionError: assert ['pending', 'pending', 'complete'] == ['failed', 'failed', 'complete']
  
  At index 0 diff: 'pending' != 'failed'
  
  Full diff:
    [
  -     'failed',
  -     'failed',
  +     'pending',
  +     'pending',
        'complete',
    ]

(CI Log)