Migration fails due to test calls no longer being tests

Description
The migration fails when there is a test call that points to an issue that is no longer a Test.

How to reproduce

1. Create 2 tests (A and B)
2. Add 2 steps to test A and call test B
3. Change issue type of test B to something else
4. Create a test execution
5. Link test A with the execution, but do not start the test run
6. Migrate

Actual result/Attachments
It will result on an exception, like this and the process will end

java.lang.IllegalArgumentException: Issue 'TEST-B' is not of type Test 

Expected result

It should migrate without any issue