Bug#731261: transition: Qt5 switching qreal == double for all platforms

[peter green <plugwash@p10link.net>]

> Please check qgis, that did FTBFS on arm* with
>   deduced conflicting types for parameter 'const T' ('double' and 'qreal {aka float}')
>   
qgis seems to be using qt4. The qreal==double on all platforms switch 
was only for qt5 (it's way too late to make such a change in qt4 now).