fix missing inline classes

[ppython]

trafficstars

The use of the InlineModelAdmin.classes attr was missing in your inline template rewriting.

With the following code using this classes inline attr, which is needed for my uses cases, I don't have them rendered:

class MyBeautifulInline(NestedStackedInline):
    # masked code unrelevant for the exemple
    
    # The Inline classes attr
    classes = ("i_want_thisclass", "i_want_thisclass2")

With this change; I now have, as excptected, an output for my stacked nested inline with the two desired classes used in my example:

<div class="inline-group" id="whateveradmin-group">
    <div class="inline-related i_want_thisclass i_want_thisclass2 dynamic-whateveradmin" id="whateveradmin-0">