GTK: Fix line edit background color with custom brush
GTK: Fix line edit background color with custom brush

We should allways use the brush and not the color if possible.

Task-number: 240842
Reviewed-by: nrc

igor-sfdc/qt-wk,radekp/qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,KDE/qt,igor-sfdc/qt-wk,KDE/qt,pruiz/wkhtmltopdf-qt,KDE/qt,igor-sfdc/qt-wk,radekp/qt,radekp/qt,pruiz/wkhtmltopdf-qt,RLovelett/qt,igor-sfdc/qt-wk,RLovelett/qt,igor-sfdc/qt-wk,KDE/qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,KDE/qt,RLovelett/qt,igor-sfdc/qt-wk,RLovelett/qt,radekp/qt,igor-sfdc/qt-wk,radekp/qt,igor-sfdc/qt-wk,radekp/qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,KDE/qt,radekp/qt,RLovelett/qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,KDE/qt,KDE/qt,RLovelett/qt,igor-sfdc/qt-wk,radekp/qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,radekp/qt,RLovelett/qt,radekp/qt,RLovelett/qt,RLovelett/qt