Seeing many failed approveWithdrawal transactions on stage

[Rizato]

Describe the bug withdrawalApprovals on stage are failing more than expected. In most cases we are seeing only two approvals retrieved from the contract before it reaches the end of the list. It is not the same two verifiers each time. ~I am wondering if there is an error retrieving more than two verifiers causing the relay to think it hasn't voted even though it has.~ This cannot be the case, else they would be marked as processed and wouldn't get to the checking verifiers stage.

To Reproduce Steps to reproduce the behavior: Look at datadog. I am going to add more verifiers locally and see if that reproduces it too.

Expected behavior I would expect there to be no failures on stage. (or nearly none)

Additional context Example https://app.datadoghq.com/logs?cols=%5B%22core_host%22%2C%22tag_swarm_service%22%2C%22tag_poly_work%22%2C%22tag_container_name%22%2C%22tag_engine_name%22%5D&event=AAAAAWg5a1DRnILKDgAAAABBV2c1YTFEUkE1X1RwUVUyUzdFNQ&from_ts=1547150964600&index=main&live=true&query=poly_work%3Astage+container_name%3A%2Arelay%2A&stream_sort=desc&to_ts=1547151864600

[Rizato]

Out of NCT on relay contract addr. Closing in favor of polyswarm/contractor#26