Fix post_process_fieldsets: This filter is only called for FeinCMS inlines anyway
Fix post_process_fieldsets: This filter is only called for FeinCMS inlines anyway

Thanks to mjl for the report and help in fixing the issue.

matthiask/django-content-editor,matthiask/feincms2-content,mjl/feincms,nickburlett/feincms,michaelkuty/feincms,feincms/feincms,joshuajonah/feincms,nickburlett/feincms,joshuajonah/feincms,pjdelport/feincms,pjdelport/feincms,feincms/feincms,joshuajonah/feincms,michaelkuty/feincms,nickburlett/feincms,matthiask/django-content-editor,nickburlett/feincms,joshuajonah/feincms,matthiask/django-content-editor,matthiask/django-content-editor,feincms/feincms,matthiask/feincms2-content,matthiask/feincms2-content,mjl/feincms,michaelkuty/feincms,mjl/feincms,michaelkuty/feincms,pjdelport/feincms