[LyX/master] Drop C++17 if init-statements to support older compilers.

[Richard Kimberly Heck]

On 11/16/22 14:29, Pavel Sanda wrote:
> commit d9847302359b7f6d5ca02b97b3b323d7f6bc3df7
> Author: Pavel Sanda <sanda at lyx.org>
> Date:   Wed Nov 16 21:23:01 2022 +0100
>
>      Drop C++17 if init-statements to support older compilers.

I find this syntax hard to read anyway. I'd personally support making it 
part of our coding style that we do not use it.

Riki