displays scrollbars by default when not required

The scroll bar is needed since the "Show my Ubuntu One folder" is not completely shown. I've asked the reporter about this report and this is the summary:

(12:10:06 PM) nessita: hi seb128! in bug #761731 I think you missed the fact that the scroll bar is indeed required, see how the "Show me my Ubuntu One folder" is not complete in the screenshot
(12:11:21 PM) seb128: nessita, hey, sorry if the "not required" was not rightly worded but the dialog takes half of the vertical screen space so I would rather like to see the dialog taking a few extra pixels and not having a scrollbar ;-)
(12:13:05 PM) nessita: seb128: I see. The problem is that once you install the package, you will get more stuff there, and we want to avoid resizing the contents, so we need to save that space beforehand
(12:13:14 PM) nessita: seb128: not sure if my explanation makes sense :-/
(12:13:48 PM) seb128: nessita, well it seems that with 15 extra pixels you would have no scrollbar displayed but they would still display later if required, anyway it's a detail
(12:14:27 PM) seb128: nessita, the first time I had a lot of empty space, like half the scrollarea widget but it didn't happen again when I tried again for the screeenshot
(12:14:29 PM) nessita: seb128: right, but that is highly dependent on the font (size, dpi) you're using, so we should not rely on that...
(12:16:21 PM) nessita: seb128: we have another bug reporting that some of the widgets are not properly drawn in the services tab, see bug #750309
(12:16:33 PM) nessita: seb128: maybe that was the issue you are referrring to?
(12:18:19 PM) seb128: nessita, no, but it seems like it's doing some show,hide on start, I can see the scrollbar being half scrolled for a one second and then it switches to the normal position
(12:18:31 PM) seb128: nessita, but don't worry about it, just close my bug