[midPoint-git] [Evolveum/midpoint] 6d62ae: Fix deletion of assignments with policy rules

[mederly]

  Branch: refs/heads/support-4.0
  Home:   https://github.com/Evolveum/midpoint
  Commit: 6d62ae92a62c466672d6c0e057cc69c8c36ec9e6
      https://github.com/Evolveum/midpoint/commit/6d62ae92a62c466672d6c0e057cc69c8c36ec9e6
  Author: Pavol Mederly <mederly at evolveum.com>
  Date:   2021-09-10 (Fri, 10 Sep 2021)

  Changed paths:
    M model/model-impl/src/main/java/com/evolveum/midpoint/model/impl/lens/projector/policy/evaluators/ConstraintEvaluatorHelper.java
    M model/model-intest/src/test/java/com/evolveum/midpoint/model/intest/rbac/TestRbac.java
    A model/model-intest/src/test/resources/rbac/global-policy-rules-assignment-deletion.xml
    A model/model-intest/src/test/resources/rbac/role-non-unassignable.xml

  Log Message:
  -----------
  Fix deletion of assignments with policy rules

There was a NPE caused by asking for the definition of the new
value of the assignment (that does not exist anymore).

This resolves MID-7039.