Trying to make bullet a little more robust to tunnelling

modules/bullet/rigid_body_bullet.cpp

@@ -751,7 +751,7 @@ void RigidBodyBullet::set_continuous_collision_detection(bool p_enable) {
 	if (p_enable) {
 		// This threshold enable CCD if the object moves more than
 		// 1 meter in one simulation frame
-		btBody->setCcdMotionThreshold(1e-7);
+		btBody->setCcdMotionThreshold(1e-6);
 
 		/// Calculate using the rule writte below the CCD swept sphere radius
 		///     CCD works on an embedded sphere of radius, make sure this radius