mongod incorrectly allows config servers to be started without journaling if specified in the config file

Config servers require journaling to be on to support committed reads. If you try to specify --nojournal with --configsvr on the command line, we correctly error. If, however, you specify storage.journal.enabled:false in a config file along with sharing.clusterRole:configsvr, we allow it. This can cause all majority reads against the config servers to fail, rendering the cluster unusable.