Steps to reproduce:
1) deploy two processes one with key X and the other with key Y. Both processes should contain an async service task
2) start a process instance of X (the service task should fail)
3) create a migration mapping from X to Y. Map the failing service task of X to the async service task of Y
4) execute the migration

Problem:
The field Job#ProcessDefinitionKey is not updated to Y.

Expected behavior:
The field Job#ProcessDefinitionKey is updated to Y.