Bugfix property groups management: fixed removing products / properties from a group.
Bugfix property groups management: fixed removing products / properties from a group.

baffolobill/django-lfs,baffolobill/django-lfs,diefenbach/django-lfs,baffolobill/django-lfs,pigletto/django-lfs,leadbrick/django-lfs,diefenbach/django-lfs,diefenbach/django-lfs,wisonwang/django-lfs,leadbrick/django-lfs,wisonwang/django-lfs,wisonwang/django-lfs,pigletto/django-lfs,pigletto/django-lfs,leadbrick/django-lfs