Release 6.20.0: The property c.o.cookie.hash.fields has been added

[changerequest]

That property allows to define additional HTTP headers that are added to the calculation of hash for the cookies. It is defined but commented in the configuration file server.properties. The calculation always includes client parameter of login request and HTTP header User-Agent. This is sufficient for most cases. So the property does not define any additional HTTP headers to include by default and it is commented.