[catboost/java] add comment; that is one of the resons why right now we can't build .jar on our Moscow zombie
#
# Regenerate JNI headers for
#
+# NOTE: doesn't work with JDK 10 because javah was removed [1] from JDK, and javac doesn't seem to
+# be able to generate native headers from .class files.
+#
# NOTE: this script must be python2/3 compatible
from __future__ import absolute_import, print_function
