Add optional dependency of PROTOBUF to VW_CARTOGRAPHY
Add optional dependency of PROTOBUF to VW_CARTOGRAPHY

Kyle's new code has modified VW_CARTOGRAPHY to require this.

DougFirErickson/StereoPipeline,NeoGeographyToolkit/StereoPipeline,oleg-alexandrov/StereoPipeline,njwilson23/StereoPipeline,ScottMcMichael/StereoPipeline,DougFirErickson/StereoPipeline,oleg-alexandrov/StereoPipeline,NeoGeographyToolkit/StereoPipeline,ScottMcMichael/StereoPipeline,aaronknister/StereoPipeline,DougFirErickson/StereoPipeline,njwilson23/StereoPipeline,NeoGeographyToolkit/StereoPipeline,aaronknister/StereoPipeline,ScottMcMichael/StereoPipeline,njwilson23/StereoPipeline,ScottMcMichael/StereoPipeline,aaronknister/StereoPipeline,oleg-alexandrov/StereoPipeline,aaronknister/StereoPipeline,ScottMcMichael/StereoPipeline,oleg-alexandrov/StereoPipeline,ScottMcMichael/StereoPipeline,oleg-alexandrov/StereoPipeline,NeoGeographyToolkit/StereoPipeline,aaronknister/StereoPipeline,oleg-alexandrov/StereoPipeline,njwilson23/StereoPipeline,DougFirErickson/StereoPipeline,NeoGeographyToolkit/StereoPipeline,njwilson23/StereoPipeline,njwilson23/StereoPipeline,DougFirErickson/StereoPipeline,DougFirErickson/StereoPipeline,NeoGeographyToolkit/StereoPipeline