build_all_installers.sh greps crosser.txt for "CROSSER_QT" instead of "CROSSER_QT5"
build_all_installers.sh checks if crosser environment has Qt available by checking CROSSER_QT from crosser.txt. As the crosser based build works only with Qt5, it should check specifically CROSSER_QT5.
build_all_installers.sh checks if crosser environment has Qt available by checking CROSSER_QT from crosser.txt. As the crosser based build works only with Qt5, it should check specifically CROSSER_QT5.