[website] missing parenthesis in java example.

website/src/react-native/index.js

@@ -291,7 +291,7 @@ public class MyCustomModule extends ReactContextBaseJavaModule {
 // Available as NativeModules.MyCustomModule.processString
   @ReactMethod
   public void processString(String input, Callback callback) {
-    callback.invoke(input.replace("Goodbye", "Hello");
+    callback.invoke(input.replace("Goodbye", "Hello"));
   }
 }
 `}