ITI-65; relax requirement for forbidding entryUUID

[oliveregger]

We've got an error message where we think that the NIST Toolkit is too strict, MHD has relaxed the requirement concerning the entryUUID:

https://profiles.ihe.net/ITI/MHD/ITI-65.html#:~:text=Except%20that%20the%20Document%20Source%20does%20not%20need%20to%20provide%20any%20entryUUID%20values%2C%20as%20the%20entryUUID%20will%20be%20populated%20by%20the%20Document%20Recipient%20when%20necessary.

Except that the Document Source does not need to provide any entryUUID values, as the entryUUID will be populated by the Document Recipient when necessary.