Add config migration for named entity death logging option (#6390)

patches/server/0188-Upstream-config-migrations.patch

@@ -0,0 +1,35 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Mark Vainomaa <mikroskeem@mikroskeem.eu>
+Date: Mon, 26 Mar 2018 18:30:53 +0300
+Subject: [PATCH] Upstream config migrations
+
+This patch contains config migrations for when upstream adds options
+which Paper already had.
+
+diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java
+index 8007220fa0646414c9cec66161aca2394e62dde3..6b952280399833eec54a72e87d916e65ae4c7339 100644
+--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
++++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
+@@ -288,4 +288,22 @@ public class PaperConfig {
+     private static void authenticationServersDownKickMessage() {
+         authenticationServersDownKickMessage = Strings.emptyToNull(getString("messages.kick.authentication-servers-down", authenticationServersDownKickMessage));
+     }
++
++    private static void savePlayerData() {
++        Object val = config.get("settings.save-player-data");
++        if (val instanceof Boolean) {
++            SpigotConfig.disablePlayerDataSaving = !(Boolean) val;
++            SpigotConfig.config.set("players.disable-saving", SpigotConfig.disableAdvancementSaving);
++            SpigotConfig.save();
++        }
++    }
++
++    private static void namedEntityDeaths() {
++        Object val = config.get("settings.log-named-entity-deaths");
++        if (val instanceof Boolean bool && !bool) {
++            SpigotConfig.logNamedDeaths = false;
++            SpigotConfig.config.set("settings.log-named-deaths", false);
++            SpigotConfig.save();
++        }
++    }
+ }