scripts/install.sh: add openSUSE Leap 15.4
Fixes
@@ -339,6 +339,7 @@ main() {
if [ "$VERSION" != "leap/15.1" ] && \
[ "$VERSION" != "leap/15.2" ] && \
[ "$VERSION" != "leap/15.3" ] && \
+ [ "$VERSION" != "leap/15.4" ] && \
[ "$VERSION" != "tumbleweed" ]
then
OS_UNSUPPORTED=1
