"TlsException: Handshake failed - error code: UNITYTLS_INTERNAL_ERROR, verify result: UNITYTLS_X509VERIFY_FATAL_ERROR" when sending a message to Azure IoT Hub using the client SDK

Reproduction steps:

1. Open "New Unity Project.zip" project
2. Open "SampleScene" scene
3. Enter Playmode
4. Notice an error: "TlsException: Handshake failed - error code: UNITYTLS_INTERNAL_ERROR, verify result: UNITYTLS_X509VERIFY_FATAL_ERROR"

Expected Result: No errors appear
Actual Result: Error appears

Fixed in: 2019.2.0a4, 2019.1.0a1, 2018.3.0a4

Reproduced with: 2018.3.0a3, 2018.2.20f1, 2018.2.0f10, 2018.2.0f1, 2018.2.0b1, 2018.2.0a7
Did not reproduce on: 2019.2.0a1, 2019.1.0a14, 2018.3.3f1, 2018.3.0a4, 2017.4.18f1 (Can't compile due to broken .dll files), 2018.2.0a4, 2018.2.0a1, 2018.1.9f2