Fix memory errors when no rigid bodies existed
Fix memory errors when no rigid bodies existed

dariomangoni/chrono,Milad-Rakhsha/chrono,jcmadsen/chrono,amelmquist/chrono,jcmadsen/chrono,amelmquist/chrono,jcmadsen/chrono,tjolsen/chrono,andrewseidl/chrono,amelmquist/chrono,armanpazouki/chrono,jcmadsen/chrono,Milad-Rakhsha/chrono,rserban/chrono,tjolsen/chrono,armanpazouki/chrono,projectchrono/chrono,jcmadsen/chrono,tjolsen/chrono,dariomangoni/chrono,rserban/chrono,dariomangoni/chrono,rserban/chrono,armanpazouki/chrono,projectchrono/chrono,Milad-Rakhsha/chrono,projectchrono/chrono,Milad-Rakhsha/chrono,amelmquist/chrono,andrewseidl/chrono,Milad-Rakhsha/chrono,Milad-Rakhsha/chrono,projectchrono/chrono,rserban/chrono,tjolsen/chrono,jcmadsen/chrono,rserban/chrono,projectchrono/chrono,jcmadsen/chrono,amelmquist/chrono,projectchrono/chrono,armanpazouki/chrono,armanpazouki/chrono,dariomangoni/chrono,andrewseidl/chrono,dariomangoni/chrono,tjolsen/chrono,andrewseidl/chrono,andrewseidl/chrono,armanpazouki/chrono,amelmquist/chrono,rserban/chrono,dariomangoni/chrono,rserban/chrono