Fix Cannot be adventure component serialized when the legacy component is null (#5754)

Spigot-Server-Patches/Adventure.patch

@@ -606,7 +606,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +    // Component
 +
 +    public static Component asAdventure(final IChatBaseComponent component) {
-+        return GSON.serializer().fromJson(IChatBaseComponent.ChatSerializer.toJsonTree(component), Component.class);
++        return component == null ? Component.empty() : GSON.serializer().fromJson(IChatBaseComponent.ChatSerializer.toJsonTree(component), Component.class);
 +    }
 +
 +    public static ArrayList<Component> asAdventure(final List<IChatBaseComponent> vanillas) {