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

Start by reproducing the failure after rebuilding in Xcode and launching the iOS Simulator, then review the provided Xcode socket and TLS log around the timeout. Done means the debugger socket remains usable after a rebuild and the simulator no longer crashes or requires Command+R to recover.

Vom Indexierungsmodell aus dem Issue-Text verfasst.