Disable preview scroll if the content fits on the screen
Disable preview scroll if the content fits on the screen

Close #1540

junegunn/fzf,infokiller/fzf,junegunn/fzf,infokiller/fzf,infokiller/fzf,janlazo/fzf,janlazo/fzf,junegunn/fzf,janlazo/fzf