title: java.net.SocketTimeoutException with Retrofit
body: <p>I'm using Retrofit and OkHttp to connect to server.
  in most times it works good. but is some case it fail.
  some times HTTP <strong>FAILED: java.net.UnknownHostException</strong> and some times  <strong>java.net.SocketTimeoutException</strong>. this error is just when I'm using home wifi to connect to server. but when I use mobile network it is good and there is no problem.
  using with emulator is good. it happens just with real device. and just some times not all times.</p>
  
  <pre><code>OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
      httpClient.readTimeout(30, TimeUnit.SECONDS)
              .connectTimeout(30, TimeUnit.SECONDS)
              .writeTimeout(30, TimeUnit.SECONDS)
              .build();
  
  
  
      retrofit = new Retrofit.Builder()
              .baseUrl(ClientConfigs.REST_API_BASE_URL)
              .addConverterFactory(GsonConverterFactory.create())
              .client(httpClient.build())
              .build();
  
  
  compile 'com.squareup.retrofit2:retrofit:2.2.0'
   compile 'com.squareup.retrofit2:converter-gson:2.1.0'
  </code></pre>