Malformed URI throws Null Reference Exception

[aamburn]

This throws a null reference exception:

var uri = "otpauth://totp/Test?&issuer=Test"; var totp = OtpCoreTotp.GetAuthenticator(uri);

Stacktrace:

Object reference not set to an instance of an object. at Petrsnd.OtpCore.OtpAuthUri..ctor(Uri uri) in ..\OtpCore\OtpCore\OtpAuthUri.cs:line 104 at Petrsnd.OtpCore.Totp.GetAuthenticator(Uri uri) in ..\OtpCore\OtpCore\Totp.cs:line 62 at Petrsnd.OtpCore.Totp.GetAuthenticator(String uriString) in ..\OtpCore\OtpCore\Totp.cs:line 57

[petrsnd]

Fixed by #23