appveyor: use Qt 5.15.2 instead
appveyor: use Qt 5.15.2 instead

kripton/qlcplus,plugz/qlcplus,sbenejam/qlcplus,mcallegari/qlcplus,plugz/qlcplus,sbenejam/qlcplus,mcallegari/qlcplus,kripton/qlcplus,sbenejam/qlcplus,mcallegari/qlcplus,plugz/qlcplus,kripton/qlcplus,kripton/qlcplus,sbenejam/qlcplus,mcallegari/qlcplus,sbenejam/qlcplus,kripton/qlcplus,kripton/qlcplus,sbenejam/qlcplus,mcallegari/qlcplus,kripton/qlcplus,plugz/qlcplus,mcallegari/qlcplus,sbenejam/qlcplus,plugz/qlcplus,mcallegari/qlcplus,plugz/qlcplus,plugz/qlcplus