[Bleeding] Cleanup clone methods.

By: Wesley Wolfe <weswolf@aol.com>

paper-api/src/main/java/org/bukkit/material/Sign.java

@@ -227,4 +227,9 @@ public class Sign extends MaterialData implements Attachable {
     public String toString() {
         return super.toString() + " facing " + getFacing();
     }
+
+    @Override
+    public Sign clone() {
+        return (Sign) super.clone();
+    }
 }