Fix compilation error for ranges with ADL begin/end

[rbrugo]

This PR should fix an issue that occurs when the range formatter is unable to use begin and end found by ADL.
For example, this code currently fails to compile:

namespace adl
{
struct box
{
    int value;
};

int * begin(box & b) noexcept { return std::addressof(b.value); }
int * end(box & b)   noexcept { return std::addressof(b.value) + 1; }

int const * begin(box const & b) noexcept { return std::addressof(b.value); }
int const * end(box const & b)   noexcept { return std::addressof(b.value) + 1; }
} // namespace adl

int main()
{
    auto x = adl::box{42};
    
    // this works
    for (auto elem : x) {
        fmt::print("{}\n", elem);
    }
    
    // this compiles correctly
    static_assert(fmt::is_range<adl::box, char>::value, "");

    // but this does not compile
    fmt::print("{}\n", x);
}

but with the proposed patch works as expected.

[phprus]

please apply clang-format

[rbrugo]

I completely forgot to run it on the tests. Thank you for pointing out.

[vitaut]

Thanks for the PR.

[vitaut]

Thank you!