After update Xcode to version Version 7.3 (7D175) "Ambguod use of subscript"

[chiarotto]

After updating Xcode I get the following error during compilation: "Ambiguos use of subscript". I fix the issue modifying the code:

func prefferedLocale() -> NSLocale {
        let langs:[String] = NSLocale.preferredLanguages()
        let identifier: String = langs[0] as! String
        let locale = NSLocale(localeIdentifier: identifier)
        return locale
    }

[fedepo]

fixed, thanks!