Fix build with INVARIANT_SUPPORT enabled but not INVARIANTS.
Fix build with INVARIANT_SUPPORT enabled but not INVARIANTS.

Reported by:	"Matthew D. Fuller" <fullermd@over-yonder.net>

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase