Preferred (11) JDK and NetBSD

[David Brownlee <abs%absd.org@localhost>]

Currently mk/java-vm.mk has

_PKG_JVMS.9=           adoptopenjdk11-bin openjdk-bin openjdk11

Which sets the default JVM to adoptopenjdk11-bin when USE_JAVA2=9

This is not an ideal situation for NetBSD, as both adoptopenjdk11-bin
and openjdk-bin are Linux binaries. In this case openjdk11 would
probably make a better default. Would anyone object to me adjusting
this to:

+# adoptopenjdk11-bin openjdk-bin do not provide native NetBSD binaries
+.if ${OPSYS} == "NetBSD"
+_PKG_JVMS.9=           openjdk11 adoptopenjdk11-bin openjdk-bin
+.else
 _PKG_JVMS.9=           adoptopenjdk11-bin openjdk-bin openjdk11
+.endif

Thanks

David