No license definition should be flagged as invalid

[vargenau]

nolicense.spdx.txt

We have:

PackageLicenseConcluded: LicenseRef-scancode-ws-policy-specification

But the definition of LicenseRef-scancode-ws-policy-specification is not provided.

This should be flagged as invalid SPDX.

Python tools say it is valid.

Java tools say:

This SPDX Document is not valid due to:
	Relationship at line 21 invalid: License not found for LicenseRef-scancode-ws-policy-specification in foo
	Package at line 13 invalid: License not found for LicenseRef-scancode-ws-policy-specification in foo
	Relationship error: License not found for LicenseRef-scancode-ws-policy-specification in foo in foo