Fix main thread priority being lowered (#9488)

patches/server/Improve-Server-Thread-Pool-and-Thread-Priorities.patch

@@ -83,10 +83,10 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
 @@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
-         S s0 = serverFactory.apply(thread); // CraftBukkit - decompile error
- 
-         atomicreference.set(s0);
+         thread.setUncaughtExceptionHandler((thread1, throwable) -> {
+             MinecraftServer.LOGGER.error("Uncaught exception in server thread", throwable);
+         });
 +        thread.setPriority(Thread.NORM_PRIORITY+2); // Paper - boost priority
-         thread.start();
-         return s0;
+         if (Runtime.getRuntime().availableProcessors() > 4) {
+             thread.setPriority(8);
          }