Fix `control socket: Protocol not supported' failure in standalone -D mode when neither -4 nor -6 is specified.
Fix `control socket: Protocol not supported' failure in
standalone -D mode when neither -4 nor -6 is specified.

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