[azuremessaging] fix typo in binding selector name
[azuremessaging] fix typo in binding selector name

bholmes/XamarinComponents,bholmes/XamarinComponents,mattleibow/XamarinComponents,JonDouglas/XamarinComponents,mattleibow/XamarinComponents,mattleibow/XamarinComponents,bholmes/XamarinComponents,bholmes/XamarinComponents,topgenorth/XamarinComponents,bholmes/XamarinComponents,xamarin/XamarinComponents,JonDouglas/XamarinComponents,JonDouglas/XamarinComponents,mattleibow/XamarinComponents,topgenorth/XamarinComponents,xamarin/XamarinComponents,xamarin/XamarinComponents,topgenorth/XamarinComponents,topgenorth/XamarinComponents,xamarin/XamarinComponents,bholmes/XamarinComponents,xamarin/XamarinComponents,xamarin/XamarinComponents,JonDouglas/XamarinComponents