There are some places where a collMod sent directly to a shard (i.e. a mongod with sharding Grid initialized) may try to contact the CSRS: 1, 2.

This is problematic during demotion of config server to replica set, as nodes are being progressively restarted without --configsvr:

• The test sends the collMod to a node that still has --configsvr.
• That node still has the Grid initialized so it will try to read from some member of the CSRS (NB: it doesn't self-route).
• It happens to pick another member of the CSRS that has already been restarted without --configsvr.
• Since that member is not a config server anymore this causes an InvalidOptions "Surprised to discover that XYZ does not believe it is a config server" error.

We have decided to accept this error so we are going to retry it as a test only failure.