Fix show_matching highlighter when opening char is the first buffer char
Fix show_matching highlighter when opening char is the first buffer char

Fixes #119

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