After creating a WebSocket, if the device is locked and unlocked, the app crashes if HTTPS is used.

Steps to reproduce:
1) Open the attached project.
2) Build for iOS.
3) Run on a device.
4) Click the 'Connect' UI button.
5) Wait for a message saying 'Connect' to appear.
6) Lock the device.
7) Unlock the device/return to app.

A crash occurs in:
thread #1: tid = 0x2113c, 0x000000018ee09188 libsystem_kernel.dylib`mach_msg_trap + 8, queue = 'com.apple.main-thread', stop reason = signal SIGPIPE

This happens with both IL2CPP and Mono2x. Does not occur on Android.
Changing the address in the input field before step 4 to 'HTTP' instead of 'HTTPS' resolves the crash.

Reproduced on:
5.5.0p3, 5.6.0b3

Devices tested:
iPhone 7 Plus iOS 10.2, iPhone 7 iOS 10.2.1