Fixes leak when creating bullet shape

modules/bullet/space_bullet.cpp

@@ -177,6 +177,7 @@ bool BulletPhysicsDirectSpaceState::cast_motion(const RID &p_shape, const Transf
 	bt_xform_to.getOrigin() += bt_motion;
 
 	if ((bt_xform_to.getOrigin() - bt_xform_from.getOrigin()).fuzzyZero()) {
+		shape->destroy_bt_shape(btShape);
 		return false;
 	}