Fix font rowHeight for negative leading spaces
Fix font rowHeight for negative leading spaces

- Qt fontmetrics may have a font lineSpacing that is smaller than
  the height (if the font leading is negative), for the row heigh
  we need to use the larger value.

ravloony/neovim-qt,0x90sled/neovim-qt,Pireax/neovim-qt,ngkaho1234/neovim-qt,ravloony/neovim-qt,ngkaho1234/neovim-qt,equalsraf/neovim-qt,Pireax/neovim-qt,ravloony/neovim-qt,equalsraf/neovim-qt,Pireax/neovim-qt,equalsraf/neovim-qt,0x90sled/neovim-qt,ngkaho1234/neovim-qt,equalsraf/neovim-qt,0x90sled/neovim-qt