Don't draw an empty button for the spacer

If it needs anything more advanced I am not sure how much I can do, and might need a lot more help

I am thinking the advanced spacing changes done for breeze probably isn't needed though, this is what it looks like now

Before this, spacers looked like this

But now, this is what the spacer looked like from an old screenshot when I was using KDE 4, so they are back to the way they used to look