fix bug with cpu_particle_2d_align_y

scene/2d/cpu_particles_2d.cpp

@@ -840,7 +840,7 @@ void CPUParticles2D::_particles_process(float p_delta) {
 		if (flags[FLAG_ALIGN_Y_TO_VELOCITY]) {
 			if (p.velocity.length() > 0.0) {
 
-				p.transform.elements[0] = p.velocity.normalized();
+				p.transform.elements[1] = p.velocity.normalized();
 				p.transform.elements[0] = p.transform.elements[1].tangent();
 			}