minor collision detection fix
minor collision detection fix

griever989/PhysicsJS,wellcaffeinated/PhysicsJS,VANITAX/PhysicsJS,Luwdo/PhysicsJS,Rawneed/PhysicsJS,mcanthony/PhysicsJS,jpellerin/PhysicsJS,wellcaffeinated/PhysicsJS,Nayar/PhysicsJS,Luwdo/PhysicsJS,rohit765/PhysicsJS,Rawneed/PhysicsJS,Nayar/PhysicsJS,jpellerin/PhysicsJS,VANITAX/PhysicsJS,rohit765/PhysicsJS,griever989/PhysicsJS,eric-seekas/PhysicsJS,mcanthony/PhysicsJS,pietro909/PhysicsJS,pietro909/PhysicsJS,haithemaraissia/PhysicsJS,eric-seekas/PhysicsJS,haithemaraissia/PhysicsJS