Re-enable parallel omp for in Chrono::Parallel rigid body update
Re-enable parallel omp for in Chrono::Parallel rigid body update

dariomangoni/chrono,rserban/chrono,projectchrono/chrono,dariomangoni/chrono,Milad-Rakhsha/chrono,rserban/chrono,rserban/chrono,Milad-Rakhsha/chrono,rserban/chrono,rserban/chrono,Milad-Rakhsha/chrono,Milad-Rakhsha/chrono,projectchrono/chrono,dariomangoni/chrono,dariomangoni/chrono,Milad-Rakhsha/chrono,projectchrono/chrono,rserban/chrono,dariomangoni/chrono,projectchrono/chrono,rserban/chrono,projectchrono/chrono,projectchrono/chrono,dariomangoni/chrono,Milad-Rakhsha/chrono