Prune redundant module descriptor

[sormuras]

Example from https://github.com/jbee/silk/tree/master/src/se.jbee.inject with main/java-8 and main/java-9, i.e. MR-JAR, directory layout

jar --list --file se.jbee.inject@19.1-ea.jar
module-info.class
META-INF/
META-INF/MANIFEST.MF
META-INF/versions/9/
META-INF/versions/9/module-info.class
se/
se/jbee/
se/jbee/inject/
se/jbee/inject/action/
se/jbee/inject/action/Action.class
...

Redundant entries:

META-INF/versions/9/
META-INF/versions/9/module-info.class

Solution: skip --release 9-block when call jar.

See also jbee/purejin#82

[sormuras]

Done via e173c62#diff-818140e2377cc7152139af83d36a751fR202