set plr velocity to 0 when denying move event

src/main/java/net/pietru/cookie_utils/mixins/PlayerPositionMixin.java

@@ -47,6 +47,7 @@ public class PlayerPositionMixin {
 
                 Vector3 new_pos = player.getPosition().cpy().sub(position);
                 player.getEntity().velocity.set(0,0,0);
+                player.getEntity().onceVelocity.set(0,0,0);
 
                 PlayerPositionPacket plr_packet = new PlayerPositionPacket(player);
                 plr_packet.position.add(new_pos);