Replace if-None checks with ternary operator in TemplateDoesNotExist.init

[Pravin]

I noticed TemplateDoesNotExist.__init__ could be made more readable and more clear.
Instead of this

    def __init__(self, msg, tried=None, backend=None, chain=None):
        self.backend = backend
        if tried is None:
            tried = []
        self.tried = tried
        if chain is None:
            chain = []
        self.chain = chain
        super().__init__(msg)

This could have been more simple, clear and readable like this

    def __init__(self, msg, tried=None, backend=None, chain=None):
        self.backend = backend
        self.tried   = tried if tried else []
        self.chain   = chain if chain else []
        super().__init__(msg)

[Youngkwang Yang]

since the codebase already uses the if-none pattern for initialization, I think it’s clear and consistent enough. so this seems more like a matter of style preference.
what do you think?

[Pravin]

I'm happy with either one

[Mariusz Felisiak]

There is nothing wrong with this code, and as I said (multiple times) we try to avoid unnecessary (and this is completely unnecessary) and trivial code reformatting unless it's a big problem as it creates extra noise in the history.