Fix QR url

[gsoft]

FIX - & instead ? in QR url provoke "Could`t recognize the key"

[RkVladimir]

Really, in order to work, you need to change code:
$encoderURL = sprintf( "%sotpauth://totp/%s@%s?secret=%s",$encoder, $user, $hostname, $secret);
it was
$encoderURL = sprintf( "%sotpauth://totp/%s@%s&secret=%s",$encoder, $user, $hostname, $secret);
&secret change to ?secret