Fix Plugins#load(String, boolean)

PlayWall/src/application.yml

 name: PlayWall
 version: 5.0.1
-build: 28
+build: 29
 identifier: de.tobias.playpad
 main: de.tobias.playpad.PlayPadMain
 author: Tobias Ullerich

PlayWallCore/src/de/tobias/playpad/plugin/Plugins.java

@@ -23,6 +23,7 @@ public class Plugins {
 
 	public static List<Plugin> load(String pluginInfoURL, boolean fetch) throws IOException {
 		if (plugins.isEmpty() || fetch) {
+			plugins.clear();
 			URL url = new URL(pluginInfoURL);
 
 			FileConfiguration cfg = YamlConfiguration.loadConfiguration(url.openStream());