img.getProject() no Errors if multiple parents. See #11807

Fixes errors in the OMEROweb.log when you try image.getProject() and there are multiple projects.

To test:
 Place an image in 2 Projects (using 1 or 2 Datasets) and open the Image in Image-Viewer. Check this looks OK.
 ``` $ tail -f dist/var/log/OMEROweb.log ``` while refreshing the browser and check there's no errors (see https://trac.openmicroscopy.org.uk/ome/ticket/11807 for example of errors)