Added border to generated TOTP QR code

To fix QR code not being scannable when in dark mode due to
lack of border matching background of QR code.

Fixes #2925

app/Auth/Access/Mfa/TotpService.php

@@ -54,7 +54,7 @@ class TotpService
 
         return (new Writer(
             new ImageRenderer(
-                new RendererStyle(192, 0, null, null, $color),
+                new RendererStyle(192, 4, null, null, $color),
                 new SvgImageBackEnd()
             )
         ))->writeString($url);