Fix some piston operations where pistons have their state toggled mid-operation

src/main/java/com/sk89q/worldedit/scripting/RhinoCraftScriptEngine.java

@@ -61,7 +61,7 @@ public class RhinoCraftScriptEngine implements CraftScriptEngine {
             if (e instanceof WrappedException) {
                 Throwable cause = ((WrappedException) e).getCause();
                 if (cause instanceof WorldEditException) {
-                    throw ((WrappedException) e).getCause();
+                    throw cause;
                 }
             }