Immediately after installing Tunderbird version 45, my old single line spacing for the inbox display and the folder list display changed from single line spacing to double line spacing. Now I can't see all of my folders on the same scree whereas with single line spacing everything was on the screen at the same time Now I have to scroll down to see all of my folders. I want my folder list and inbox display to be compact and single spaced! How can I change these displays back to single line spacing? Thank you.