Fix unit test TestCsvDriver.testTimestampFormatGermany that succeeded in Java 1.8 but fails in Java 11. Stack trace is:
java.lang.NullPointerException
at java.base/java.util.Calendar.setTime(Calendar.java:1800)
at java.base/java.text.SimpleDateFormat.format(SimpleDateFormat.java:974)
at java.base/java.text.SimpleDateFormat.format(SimpleDateFormat.java:967)
at java.base/java.text.DateFormat.format(DateFormat.java:374)
at org.relique.jdbc.csv.TestCsvDriver.testTimestampFormatGermany(TestCsvDriver.java:3869)