Trying to retrieve the featureCompatibilityVersion for an uninitialized replica set member on MongoDB 3.7.5 results in an invariant failure.

To reproduce:

1. Start with a basic configuration for the first node of a replica set /usr/local/mongo375/bin/mongod --dbpath 375 --replSet foo --port 27000
2. Connect to it and run db.runCommand({getParameter:1, featureCompatibilityVersion:1})
3. Check mongod logs for invariant failures

2018-04-20T19:56:09.052+0000 F -        [conn1] Invariant failure isVersionInitialized() src/mongo/db/server_options.h 207

Full log attached.