iOS: Simulator socket connection times out due to debugger

Hi there! Thanks for the debugger, I use it daily and find it very helpful. 😀

After I rebuild in Xcode and launch the simulator, the socket connection to the debugger times out roughly 5 seconds after starting the app and the simulator crashes. Once I reload the simulator using command + R, I no longer have socket connection issues until the next time I rebuild.

Here's a screenshot of the crash screen on the simulator:

Here are some excerpts from my Xcode log that may be helpful:
```
2016-12-09 16:10:56.114498 bulbasaur[21709:8268397] [] __tcp_connection_start_block_invoke 53 sending event TCP_CONNECTION_EVENT_TLS_HANDSHAKE_COMPLETE in response to state ready and error (null)
2016-12-09 16:10:56.114739 bulbasaur[21709:8268397] [] tcp_connection_event_notify 53 event: TCP_CONNECTION_EVENT_TLS_HANDSHAKE_COMPLETE, reason: nw_connection event, should deliver: true
2016-12-09 16:10:56.115090 bulbasaur[21709:8268397] [] tcp_connection_get_statistics DNS: 3ms/4ms since start, TCP: 16ms/277ms since start, TLS: 11ms/287ms since start
2016-12-09 16:11:24.680962 bulbasaur[21709:8256238] [] tcp_connection_cancel 50
2016-12-09 16:11:24.681405 bulbasaur[21709:8268396] [] nw_socket_handle_socket_event Event mask: 0x4
2016-12-09 16:11:24.681745 bulbasaur[21709:8256238] [] tcp_connection_cancel 51
2016-12-09 16:11:24.682188 bulbasaur[21709:8268396] [] nw_socket_handle_socket_event Socket received WRITE_CLOSE event
2016-12-09 16:11:24.683606 bulbasaur[21709:8268396] [] __nw_socket_service_writes_block_invoke sendmsg(fd 20, 31 bytes): socket has been closed
2016-12-09 16:11:24.683948 bulbasaur[21709:8268396] [] nw_endpoint_flow_protocol_error [50.2 *IP address* cancelled socket-flow (null)] Socket protocol sent error: [32] Broken pipe
```

cc @kkemple

まず、Xcode で再ビルドして iOS Simulator を起動した後に障害を再現し、そのうえでタイムアウト前後の、提供されている Xcode socket および TLS のログを確認します。再ビルド後もデバッガーソケットを使用でき、シミュレーターがクラッシュせず、復旧のために Command+R も必要としなくなれば完了です。

索引モデルが issue の本文から書いたものです。