[helloworld] : devserver gapi API calls are directed to remote endpoint instead localhost

[MatteoOreficeIT]

Until appengine-endpoints version 1.9.7 gapi client calls are directed to remote enpoint https://your-app-id.appspot.com/_ah/api/helloworldendpoints/v1/sayHello instead to localhost:8080 endpoint generating a 503 Service Unavailable

the helloworld:pom.xml needs to be updated with this dependency :

<dependency>
            <groupId>com.google.appengine</groupId>
            <artifactId>appengine-endpoints</artifactId>
            <version>1.9.8</version>
</dependency>