fixed the bug introduced when replacing Real4 vel with Real3
fixed the bug introduced when replacing Real4 vel with Real3

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