Bump min Qt version

[Maik Qualmann]

But we already have a problem with Qt::endl, this only exists with Qt-5.14. We 
should find another way of doing this than with pre-processeur branching. 
Maybe define a macro. 

Maik

Am Dienstag, 15. Juni 2021, 13:55:53 CEST schrieb Gilles Caulier:
> Hi,
> 
> No. We need to be compatible at least with Qt 5.12 LTS.
> Please make pre-processeur branching in source code by checking Qt version,
> as it already do in other place in digiKam.
> 
> exemple :
> https://invent.kde.org/graphics/digikam/-/blob/master/core/app/date/ddatepic
> ker.cpp#L547
> 
> Best
> 
> Gilles Caulier
> 
> Le mar. 15 juin 2021 à 13:52, Anjani Kumar <anjanik012 at gmail.com> a écrit :
> > The recent changes to
> > https://invent.kde.org/graphics/digikam/-/tree/gsoc21-qt6-port makes it
> > compile only on newer Qt versions. So I it should be best Bump Qt version
> > to 5.15.2.  Should I make the change?
> > 
> > Thanks,
> > Anjani