r9303/sofa : cmake: Check for SIMULATION_GRAPH_BGL before adding BoostKernel
r9303/sofa : cmake: Check for SIMULATION_GRAPH_BGL before adding BoostKernel


Former-commit-id: 6dc2f5b5608cb544ce0abde0fba55018db60c2e1
hdeling/sofa,Anatoscope/sofa,Anatoscope/sofa,hdeling/sofa,FabienPean/sofa,FabienPean/sofa,hdeling/sofa,Anatoscope/sofa,hdeling/sofa,hdeling/sofa,Anatoscope/sofa,hdeling/sofa,Anatoscope/sofa,Anatoscope/sofa,FabienPean/sofa,FabienPean/sofa,hdeling/sofa,Anatoscope/sofa,FabienPean/sofa,Anatoscope/sofa,FabienPean/sofa,hdeling/sofa,hdeling/sofa,FabienPean/sofa,hdeling/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,Anatoscope/sofa