Fix for hosting some linux vst windows

I found 2 issues when hosting linux vst plugin windows using juce code:

- some guis will have their bottom cut off

- when not using native titlebar the window is still resizable via WM
see, note the "resize" option is not greyed out.


Fixed those just now, patch here:

You can see both fixed here :D


Thanks, will take a look at that today!