Fix: ‘auto’ deduced as ‘id’ Xcode warning

[geraintluff]

I'm using Xcode 13.2.1, and I get a warning when auto is deduced as id. This is on by default in Clang.

This can be fixed by replacing auto with id in choc_WebView.h. This matches choc_MessageLoop.h, which is the only other place call<id> is used to initialise a variable.

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I originally opened this as PR #40, but since PRs are complicated by copyright issues, you can find the locations yourself with the RegEx auto .* = call<id>:

find . -iname \*.h -exec grep -Hn -i "auto .* = call<id>" {} \;

[julianstorer]

Thanks for the heads-up, I'll update my tests to the latest clang and make sure that warning is turned on!