src: Make sure clients connect from a TTY
src: Make sure clients connect from a TTY

Fixes #3159

occivink/kakoune,lenormf/kakoune,mawww/kakoune,casimir/kakoune,jkonecny12/kakoune,alexherbo2/kakoune,lenormf/kakoune,Somasis/kakoune,occivink/kakoune,Somasis/kakoune,jkonecny12/kakoune,jkonecny12/kakoune,danr/kakoune,danr/kakoune,mawww/kakoune,occivink/kakoune,alexherbo2/kakoune,casimir/kakoune,casimir/kakoune,jkonecny12/kakoune,casimir/kakoune,lenormf/kakoune,lenormf/kakoune,occivink/kakoune,alexherbo2/kakoune,alexherbo2/kakoune,Somasis/kakoune,Somasis/kakoune,mawww/kakoune,danr/kakoune,mawww/kakoune,danr/kakoune