do not append trailing slash to OUT_PWD in nested pro-files
do not append trailing slash to OUT_PWD in nested pro-files

the top-level one doesn't have one, either, so this lead to inconsistent
behavior depending on whether the pro was processed directly or from a
SUBDIRS target.

Reviewed-by: mariusSO

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