Resolve issue with querying session ping after it disconnected

core/src/main/java/org/geysermc/geyser/session/GeyserSession.java

@@ -2187,6 +2187,11 @@ public class GeyserSession implements GeyserConnection, GeyserCommandSource {
 
     @Override
     public int ping() {
+        // Can otherwise cause issues if the player isn't logged in yet / already left
+        if (getUpstream().isInitialized() || getUpstream().isClosed()) {
+            return 0;
+        }
+
         RakSessionCodec rakSessionCodec = ((RakChildChannel) getUpstream().getSession().getPeer().getChannel()).rakPipeline().get(RakSessionCodec.class);
         return (int) Math.floor(rakSessionCodec.getPing());
     }