I had a look at the server, but given I have no experience with tomcat and I'm not familiar with the configuration of the server and our TC installation I decided not to try to upgrade it myself, since the likelihood of my breaking something would be quite high.
Henry, any chance you can do the upgrade anytime soon, or if not, send me an email about how the tomcat is set up, if there's anything else but TeamCity running on it, and if we've made any configuration changes to TeamCity (like external database etc).