change the volume_support default to False

With volume_support enabled, trove will require that new instances use
swift. It works fine without swift though and I suppose we want to avoid
an unneeded dependency on swift.
We have done that NOWHERE, and i can absolutly not aggree on that style of code. If you should use a real IDE you would see the available attributes, if you are not doing that it's your fault.

So for me it's a :-1: for coding style.