Bug#912233: checkstyle FTBFS with OpenJDK 11

[Emmanuel Bourg]

Control: retitle: checkstyle: FTBFS with saxonhe 9.9.0
Control: user debian-j...@lists.debian.org
Control: usertag -1 - default-java11

This issue is actually caused by the upload of saxonhe 9.9.0 last week.