[1.4.x] Fixed arguments for get_inline_instances; refs #17006.

            inlines = [MyInline, SomeOtherInline]

            def get_formsets(self, request, obj=None):

                for inline in self.get_inline_instances():

                for inline in self.get_inline_instances(request):

                    # hide MyInline in the add view

                    if isinstance(inline, MyInline) and obj is None:

                        continue