Use GetFileVersion in iss file

[HashidaTKS]

We can use GetFileVersion to get version info in iss file.

In order to use GetFileVersion, we should specify the file version for the assembly info.

And, maybe it is better to use System.Reflection.Assembly.GetExecutingAssembly().GetName().Version.ToString() for Global.Version.
We should specify the same version for the assembly version and the file version if fixing to do so.

    public class Global
    {
        public static readonly string AppName = "FlexConfirmMail";
        public static readonly string Version = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version.ToString();
        public static readonly string Edition = "Enterprise";
        public static readonly bool EnableGPO = true;
    }

Originally posted by @HashidaTKS in #13 (comment)