Fix name of include guard macro in ModelDefs.h
Fix name of include guard macro in ModelDefs.h

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