Fix status code (say if the account can't be authorized)

appengine/src/com/google/android/chrometophone/server/RegisterServlet.java

@@ -74,6 +74,7 @@ public class RegisterServlet extends HttpServlet {
                 pm.close();
             }
         } else {
+            resp.setStatus(400);
             resp.getWriter().println(ERROR_STATUS + " (Not authorized)");
         }
     }