Editor crash upon closing Unity before the publish finishes.

Steps to reproduce:
1. Open any test project from collab or create a new one.
2. Make sure you have access to a project that has Collab enabled.

Follow the below steps if you are creating a new project:

1. Create a new project.
2. Right-click in Project window > Create > Material.
3. Go to Windows > General > Services
4. Select Organization you have created from the dropdown and click 'Create'.
5. Click on 'Collab' button on the upper right corner of the editor.
6. Click on 'Start Now!'.
7. Click on 'Publish now!'.
8. Before the publish finishes, close unity editor.

Note: Video is attached for reference

Actual result:
Editor crash.

Expected result:
Editor closes without a crash.

Occurring On: 2019.1.0a13, 2019.1.0a12, 2018.3.0f2, 2017.3.0f3

Environment: Windows Only.

========== OUTPUTTING STACK TRACE ==================

Refreshing native plugins compatible for Editor in 0.63 ms, found 3 plugins.
Preloading 1 native plugins for Editor in 0.22 ms.
Refreshing native plugins compatible for Editor in 0.40 ms, found 3 plugins.
Preloading 1 native plugins for Editor in 0.31 ms.

Refresh Completed time: 0.181565s
Asset Scan time: 0.022339s
Asset Hashing: 0.000000s [0 B, 0.000000 mb/s]
Asset Import (Scripting) time: 0.000000s (count: 0)
Post Processs Assets (Scripting) time: 0.000000s
Asset Rehashing: 0.000000s [0 B, 0.000000 mb/s]
Asset Import (Non Scripting) time: 0.000000s (count: 0)
Post Process Assets (Non Scripting) time: 0.000000s
Dependent Assets to Import Queue time: 0.000000s

Updating ProjectSettings/ProjectSettings.asset - GUID: 00000000000000004000000000000000...
done. [Time: 16.216145 ms]
Refreshing native plugins compatible for Editor in 0.38 ms, found 3 plugins.
Preloading 1 native plugins for Editor in 0.19 ms.
Refresh: detecting if any assets need to be imported or removed ...
Refreshing native plugins compatible for Editor in 0.45 ms, found 3 plugins.
Preloading 1 native plugins for Editor in 0.34 ms.
Refreshing native plugins compatible for Editor in 0.31 ms, found 3 plugins.
Preloading 1 native plugins for Editor in 0.27 ms.

Refresh Completed time: 0.179879s
Asset Scan time: 0.024068s
Asset Hashing: 0.000000s [0 B, 0.000000 mb/s]
Asset Import (Scripting) time: 0.000000s (count: 0)
Post Processs Assets (Scripting) time: 0.000000s
Asset Rehashing: 0.000000s [0 B, 0.000000 mb/s]
Asset Import (Non Scripting) time: 0.000000s (count: 0)
Post Process Assets (Non Scripting) time: 0.000000s
Dependent Assets to Import Queue time: 0.000000s

0x00007FF7EA0618BF (Unity) CollabTransactions::TransactionManager::DoneSubmitRequestAsyncCallback
0x00007FF7EA061A52 (Unity) CollabTransactions::TransactionManager::DoneUploadEntriesAsync
0x00007FF7EA06A6C5 (Unity) CollabTransactions::TransactionManager::UploadNewBatch
0x00007FF7E9EC4DC7 (Unity) CollabClientCloud::UploadChangesAsync
0x00007FF7E9EED0C5 (Unity) CollabPublishAsyncJob::Execute
0x00007FF7E9ED37A2 (Unity) CollabJob::DoJobCaller
0x00007FF7EAF593D8 (Unity) JobQueue::Exec
0x00007FF7EAF5F272 (Unity) JobQueue::Steal
0x00007FF7EAF59AE8 (Unity) JobQueue::ExecuteJobFromQueue
0x00007FF7EAF5B621 (Unity) JobQueue::ProcessJobs
0x00007FF7EAF5FC28 (Unity) JobQueue::WorkLoop
0x00007FF7EB2A7287 (Unity) Thread::RunThreadWrapper
0x00007FF9E9213034 (KERNEL32) BaseThreadInitThunk
0x00007FF9EBCF3691 (ntdll) RtlUserThreadStart

========== END OF STACKTRACE ===========