windowPreview: Make St.Label use single line mode
I don't know, if the fact that the window caption effects the window preview size is intentional or not. So I can't tell, if this can be considered a fix for the root of the mentioned issue. It does address the issue at least as a side effect. Regardless, it doesn't look like the window caption is meant to be multine, so Newline characters should be removed.
Edited by Leleat