Fix typo in example/src/App.jsx

[natejenkins]

(user) => this.setState({isSignedIn: !!user}
should be
(user) => this.setState({isSignedIn: !!user})

In its current form the example fails to build.

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[natejenkins]

I signed it!

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CLAs look good, thanks!

[nicolasgarnier]

Thanks @natejenkins !