Added world seed display to 'Preparing level' log message for each world

By: EvilSeph <evilseph@unaligned.org>

paper-server/src/main/java/org/bukkit/craftbukkit/CraftServer.java

@@ -401,6 +401,7 @@ public final class CraftServer implements Server {
         }
 
         pluginManager.callEvent(new WorldInitEvent(internal.getWorld()));
+        System.out.print("Preparing start region for level " + (console.worlds.size() -1) + " (Seed: " + internal.getSeed() + ")");
 
         short short1 = 196;
         long i = System.currentTimeMillis();