Updated 'Piece' class.

Updated the 'Piece' class by removing the unused 'id' parameter from the constructor.

Projekte/mdga/model/src/main/java/pp/mdga/game/Piece.java

@@ -35,12 +35,15 @@ public class Piece {
      * @param color the color of the piece
      * @param state the state of the piece
      */
-    public Piece(Color color, PieceState state, int id) {
+    public Piece(Color color, PieceState state) {
         this.color = color;
         this.state = state;
         shield = ShieldState.NONE;
     }
 
+    /**
+     * Constructor.
+     */
     private Piece() {
         color = Color.NONE;
         state = PieceState.WAITING;