Fix bug preventing group creation
Fix bug preventing group creation

The old code would throw an exception whenever trying to create a group
because the initial find would always return null for a new group.

foam-framework/foam2,jacksonic/vjlofvhjfgm,foam-framework/foam2,foam-framework/foam2,jacksonic/vjlofvhjfgm,foam-framework/foam2,foam-framework/foam2,jacksonic/vjlofvhjfgm