CI fails TestIndexWriter#testSoftUpdateDocuments

[junit4] Suite: org.apache.lucene.index.TestIndexWriter
[junit4] 2> NOTE: reproduce with: ant test -Dtestcase=TestIndexWriter -Dtests.method=testSoftUpdateDocuments -Dtests.seed=AA5B403FFC4459A5 -Dtests.slow=true -Dtests.badapples=true -Dtests.locale=fr-BE -Dtests.timezone=Antarctica/Mawson -Dtests.asserts=true -Dtests.file.encoding=ISO-8859-1
[junit4] FAILURE 0.08s J1 | TestIndexWriter.testSoftUpdateDocuments <<<
[junit4] > Throwable #1: java.lang.AssertionError: expected:<0> but was:<2>
[junit4] > at __randomizedtesting.SeedInfo.seed([AA5B403FFC4459A5:6F9256CD24240312]:0)
[junit4] > at org.apache.lucene.index.TestIndexWriter.testSoftUpdateDocuments(TestIndexWriter.java:3168)
[junit4] > at java.lang.Thread.run(Thread.java:748)
[junit4] 2> NOTE: leaving temporary files on disk at: /var/lib/jenkins/workspace/apache+lucene-solr+branch_7x/lucene/build/core/test/J1/temp/lucene.index.TestIndexWriter_AA5B403FFC4459A5-001