Fix default value of VERSION environment.
Fix default value of VERSION environment.

learningequality/installers,learningequality/ka-lite-installers,benjaoming/installers,learningequality/ka-lite-installers,benjaoming/installers,benjaoming/installers,learningequality/installers,mrpau/installers,mrpau/installers,learningequality/installers,mrpau/installers,mrpau/installers,learningequality/ka-lite-installers,learningequality/ka-lite-installers,learningequality/installers,benjaoming/installers