Model craches after creating groups in a new model

[martac]

When you create a new model, and you go to ecopath, edit groups, and add your new groups, after you say ok and save it, the model crashes and you need to open ewe again. The new groups then appear in the database that crashed. In some cases, when you open the model again you see more than one set of groups created, so there is a duplication of new groups created.

[jeroens]

Fixed, this was a bad one.

[jeroens]

The bug occurred when a group was changed while others were added or removed