A nullpointer is thrown during the migration process due to the Test Type customfield

Description

A nullpointer maybe thrown during the export phase of the migration if the Test Type customfield is either missing a Global Context or is applied to other Issue types besides Test

How to reproduce

1. Delete/remove the Global Context from the Test type field.
2. Run Server to cloud Migration

Actual result/Attachments

Migration fails on the export process and a nullpointer exception can be observed in the logs.

Expected result

Case should be handled and the migration should progress without any hiccups.

Workaround

Create a global context (if missing) and/or remove other issuetypes from the context