server: MRC: Fix error message "Error message: a default replication policy...

server: MRC: Fix error message "Error message: a default replication policy requires a replication factor >= 2 (errno=POSIX_ERROR_EPERM)" if the default replication policy is reset with "xtfsutil --set-drp --replication-policy none <mount point>". (Existing code to fix this used the wrong variable to check against.)