Fileset examples fixes 11852

Updating examples/Training/python with examples of Bliltz Gateway API changes for OMERO 5 as part of https://github.com/openmicroscopy/ome-documentation/pull/594

 - Fileset examples
 - conn.getAdministrators()
    - In running this code I found a Bug in Blitz Gateway which was fixed by subsequent commit.

To test, run the new code in the example files (substituting login and imageId as needed).