IncrementalInserter: fix append mode when on line end
IncrementalInserter: fix append mode when on line end

ekie/kakoune,danr/kakoune,alpha123/kakoune,lenormf/kakoune,jkonecny12/kakoune,jjthrash/kakoune,Somasis/kakoune,flavius/kakoune,alexherbo2/kakoune,zakgreant/kakoune,jkonecny12/kakoune,jjthrash/kakoune,elegios/kakoune,rstacruz/kakoune,casimir/kakoune,casimir/kakoune,danielma/kakoune,lenormf/kakoune,casimir/kakoune,rstacruz/kakoune,mawww/kakoune,jjthrash/kakoune,alexherbo2/kakoune,ekie/kakoune,xificurC/kakoune,zakgreant/kakoune,Asenar/kakoune,alexherbo2/kakoune,jkonecny12/kakoune,danielma/kakoune,xificurC/kakoune,flavius/kakoune,danr/kakoune,rstacruz/kakoune,zakgreant/kakoune,mawww/kakoune,lenormf/kakoune,Somasis/kakoune,mawww/kakoune,occivink/kakoune,Asenar/kakoune,danr/kakoune,occivink/kakoune,occivink/kakoune,Asenar/kakoune,jjthrash/kakoune,casimir/kakoune,alpha123/kakoune,jkonecny12/kakoune,flavius/kakoune,ekie/kakoune,mawww/kakoune,danielma/kakoune,elegios/kakoune,danielma/kakoune,Asenar/kakoune,alexherbo2/kakoune,rstacruz/kakoune,alpha123/kakoune,zakgreant/kakoune,lenormf/kakoune,Somasis/kakoune,xificurC/kakoune,occivink/kakoune,ekie/kakoune,elegios/kakoune,xificurC/kakoune,danr/kakoune,alpha123/kakoune,flavius/kakoune,Somasis/kakoune,elegios/kakoune