Some small changes

src/com/cnaude/chairs/core/Chairs.java

@@ -88,7 +88,7 @@ public class Chairs extends JavaPlugin {
 	@Override
 	public void onDisable() {
 		if (psitdata != null) {
-			for (Player player : getServer().getOnlinePlayers()) {
+			for (Player player : Utils.getOnlinePlayers()) {
 				if (psitdata.isSitting(player)) {
 					psitdata.unsitPlayerNow(player);
 				}

src/com/cnaude/chairs/core/Utils.java

@@ -0,0 +1,12 @@
+package com.cnaude.chairs.core;
+
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+
+public class Utils {
+
+	public static Player[] getOnlinePlayers() {
+		return Bukkit.getOnlinePlayers();
+	}
+
+}