bug#46299: 28.0.50; Value of tab-bar-show not respected in new frames.

[martin rudalics]

> 'toggle-frame-tab-bar' already does exactly this - sets the
> 'tab-bar-lines' parameter to non-zero, and doesn't change it
> on all other frames.
>
> But currently 'tab-bar-show' overrides this user setting,
> and affects all other frames.

I forgot.  This is inherently broken for all frame parameters and
unlikely to change ever.

martin