Sometimes transport_manager_test may fail with core crash

[dboltovskyi]

Bug Report

Sometimes transport_manager_test may fail with core crash

Reproduction Steps

1. Build SDL core with -DBUILD_TESTS=ON cmake option
2. Run transport_manager_test with command:

./transport_manager_test --gtest_filter=WebsocketNotSecureSessionConnectionTest.SUCCESS_SendData --gtest_repeat=100

Expected Behavior

Test passed

Observed Behavior

Test failed and core crash observed

OS & Version Information

• OS/Version: Ubuntu 18.04
• SDL Core Version: https://github.com/smartdevicelink/sdl_core/tree/develop (31324d5)
• Testing Against: N/A

Test Case, Sample Code, and / or Example App

• backtrace.txt

[Jack-Byrne]

@dboltovskyi Does Luxoft plan on submitting a pr for this issue?

[dboltovskyi]

@JackLivio Yes, Luxoft teams is going to submit a fix for this issue.

[jacobkeeler]

Closed via #3809