Fix shutdown on eula not being agreed (Fixes #4647)

Spigot-Server-Patches/0312-Improve-Server-Thread-Pool-and-Thread-Priorities.patch

@@ -25,10 +25,10 @@ index b13d8ec9aa0a51d5432129f1b0ecef3beb5b7276..f4c93a65c28eeca4a07aaf9b00507d5c
      }
 diff --git a/src/main/java/net/minecraft/server/ServerWorkerThread.java b/src/main/java/net/minecraft/server/ServerWorkerThread.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..1a94648cb79c8f2889aacb5fb21dc07ad84a4a6b
+index 0000000000000000000000000000000000000000..703f45da2954272a7b92e2b11087c80a11f0370d
 --- /dev/null
 +++ b/src/main/java/net/minecraft/server/ServerWorkerThread.java
-@@ -0,0 +1,25 @@
+@@ -0,0 +1,26 @@
 +package net.minecraft.server;
 +
 +import java.util.concurrent.CompletionException;
@@ -39,6 +39,7 @@ index 0000000000000000000000000000000000000000..1a94648cb79c8f2889aacb5fb21dc07a
 +    public ServerWorkerThread(Runnable target) {
 +        super(target, "Server-Worker-" + threadId.getAndIncrement());
 +        setPriority(Thread.NORM_PRIORITY-1); // Deprioritize over main
++        this.setDaemon(true);
 +        this.setUncaughtExceptionHandler((thread, throwable) -> {
 +            thread.setDaemon(true);
 +            if (throwable instanceof CompletionException) {