[wip][patch] use qmake with autoconf for qt5 too

[José Matos]

On Mon, 2024-06-17 at 17:02 +0100, José Matos wrote:
> Slightly related to your message:
> 
> When configuring autools with qt6 I get these (seemingly harmless)
> warnings.

@Jean-Marc note that these warning, for qt6, happened before your
current patch. That is why I wrote this is slightly related to this
patch.
-- 
José Abílio