math/octave: restrict required java version to 11+ (+)

octave require java-1.9+ to build java bindings and skip it if found java-1.8

checking for Java version... 1.8.0_482
configure: WARNING: Java version is too old (< 1.9). Octave will not be able to call Java methods.
...
pkg-static: Unable to access file /usr/ports/math/octave/work/stage/usr/local/share/octave/11.1.0/m/java/octave.jar:No such file or directory

Reported by: root@dc365.ru
Approved by: portmgr blanket