hg: jdk/jdk: 8210454: jar tool does not allow setting the module version without also setting the main class

[lance.andersen at oracle.com]

Changeset: f24ae8376e71
Author:    lancea
Date:      2018-11-28 14:49 -0500
URL:       http://hg.openjdk.java.net/jdk/jdk/rev/f24ae8376e71

8210454: jar tool does not allow setting the module version without also setting the main class
Reviewed-by: alanb, mchung, chegar

! src/jdk.jartool/share/classes/sun/tools/jar/Main.java
! test/jdk/tools/jar/modularJar/Basic.java