Support Java 17

[mikrobestie]

When the applyalter is run on Java 17, the following exception is thrown:

java.lang.ExceptionInInitializerError
	at com.thoughtworks.xstream.XStream.setupConverters(XStream.java:648)
	at com.thoughtworks.xstream.XStream.<init>(XStream.java:436)
	at com.thoughtworks.xstream.XStream.<init>(XStream.java:376)
	at com.thoughtworks.xstream.XStream.<init>(XStream.java:314)
	at ch.ips.g2.applyalter.ApplyAlter.<init>(ApplyAlter.java:156)
	at ch.ips.g2.applyalter.ApplyAlter.main(ApplyAlter.java:936)
Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make field protected volatile java.util.Properties java.util.Properties.defaults accessible: module java.base does not "opens java.util" to unnamed module @405e4200
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:354)
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
	at java.base/java.lang.reflect.Field.checkCanSetAccessible(Field.java:178)
	at java.base/java.lang.reflect.Field.setAccessible(Field.java:172)
	at com.thoughtworks.xstream.core.util.Fields.find(Fields.java:26)
	at com.thoughtworks.xstream.converters.collections.PropertiesConverter.<clinit>(PropertiesConverter.java:41)
	... 6 more

XStream should be updated to more recent version