null pointer exceptions for some services without presets or adjustable parameters

When a JABAWS service does not report to have any adjustable settings, Jalview throws an exception after adding the service to the service list and before adding the server to the list of valid JABAWS servers.

Exception noticed in dump posted to jalview-discuss by Charles Bridges who's having problems connecting to JABAWS.
(see full post here: http://www.jalview.org/pipermail/jalview-discuss/2012-December/000895.html )

Exception below:

> Discovered service: http://www.compbio.dundee.ac.uk/jabaws
> jalview.ws.jws2.jabaws2.Jws2Instance@187d27e
> java.lang.NullPointerException
> at jalview.ws.jws2.Jws2Discoverer.addService(Jws2Discoverer.java:253)
> at jalview.ws.jws2.JabaWsServerQuery.run(JabaWsServerQuery.java:181)
> at java.lang.Thread.run(Unknown Source)