match BioFormats bump of AssumeNG up from 1.2.3 to 1.2.4

Depends upon https://github.com/openmicroscopy/bioformats/pull/442 (probably why the Travis build failed) and allows OMERO to fully build afterward, including the test classes.

At the least, make sure that from a clean build the Blitz unit tests compile and pass. (Well, actually some of them will probably fail, just make sure that it's no more than usual -- that none of the errors look to be related to AssumeNG!)