Fix handling of changes to PlayerVelocityEvent.velocity by event callers.

nms-patches/EntityHuman.patch

@@ -315,7 +315,7 @@
 +                            if (event.isCancelled()) {
 +                                cancelled = true;
 +                            } else if (!velocity.equals(event.getVelocity())) {
-+                                player.setVelocity(velocity);
++                                player.setVelocity(event.getVelocity());
 +                            }
 +
 +                            if (!cancelled) {

nms-patches/EntityTrackerEntry.patch

@@ -89,13 +89,13 @@
 +                Player player = (Player) this.tracker.getBukkitEntity();
 +                org.bukkit.util.Vector velocity = player.getVelocity();
 +
-+                PlayerVelocityEvent event = new PlayerVelocityEvent(player, velocity);
++                PlayerVelocityEvent event = new PlayerVelocityEvent(player, velocity.clone());
 +                this.tracker.world.getServer().getPluginManager().callEvent(event);
 +
 +                if (event.isCancelled()) {
 +                    cancelled = true;
 +                } else if (!velocity.equals(event.getVelocity())) {
-+                    player.setVelocity(velocity);
++                    player.setVelocity(event.getVelocity());
 +                }
 +            }
 +