src: Fix the string conversion of range faces
src: Fix the string conversion of range faces

Fixes #1250

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