Many NoClassDefFoundError: jetbrains/exodus/core/execution/SharedTimer when executing upgrade tests

They don't impact the test result but that's one way to see them at least.

```
2020-08-07 12:55:29,675 [Exec Stream Pumper] - java.lang.NoClassDefFoundError: jetbrains/exodus/core/execution/SharedTimer$Ticker$1
2020-08-07 12:55:29,675 [Exec Stream Pumper] - at jetbrains.exodus.core.execution.SharedTimer$Ticker.execute(SharedTimer.java:99)
2020-08-07 12:55:29,675 [Exec Stream Pumper] - at jetbrains.exodus.core.execution.Job.run(Job.java:99)
2020-08-07 12:55:29,675 [Exec Stream Pumper] - at jetbrains.exodus.core.execution.ThreadJobProcessor.executeJob(ThreadJobProcessor.java:133)
2020-08-07 12:55:29,675 [Exec Stream Pumper] - at jetbrains.exodus.core.execution.JobProcessorQueueAdapter.doExecuteJob(JobProcessorQueueAdapter.java:243)
2020-08-07 12:55:29,675 [Exec Stream Pumper] - at jetbrains.exodus.core.execution.JobProcessorQueueAdapter.doTimedJobs(JobProcessorQueueAdapter.java:195)
2020-08-07 12:55:29,675 [Exec Stream Pumper] - at jetbrains.exodus.core.execution.JobProcessorQueueAdapter.doJobs(JobProcessorQueueAdapter.java:163)
2020-08-07 12:55:29,675 [Exec Stream Pumper] - at jetbrains.exodus.core.execution.ThreadJobProcessor.run(ThreadJobProcessor.java:111)
2020-08-07 12:55:29,675 [Exec Stream Pumper] - at jetbrains.exodus.core.execution.ThreadJobProcessor$1.run(ThreadJobProcessor.java:43)
2020-08-07 12:55:29,675 [Exec Stream Pumper] - at java.lang.Thread.run(Thread.java:748)
```