[contenteditable input] Don't preventDefault keypress events when charCode==0
[contenteditable input] Don't preventDefault keypress events when charCode==0

Closes #4589

ficristo/CodeMirror,notepadqq/CodeMirror,schanzer/CodeMirror,MarcelGerber/CodeMirror,nightwing/CodeMirror,SidPresse/CodeMirror,pabloferz/CodeMirror,thomasjm/CodeMirror,dperetti/CodeMirror,MarcelGerber/CodeMirror,schanzer/CodeMirror,hackmdio/CodeMirror,ejgallego/CodeMirror,ficristo/CodeMirror,dperetti/CodeMirror,wingify/CodeMirror,wingify/CodeMirror,grzegorzmazur/CodeMirror,nightwing/CodeMirror,kerabromsmu/CodeMirror,thomasjm/CodeMirror,MarcelGerber/CodeMirror,nightwing/CodeMirror,grzegorzmazur/CodeMirror,jkaplon/CodeMirror,crazy4chrissi/CodeMirror,codio/CodeMirror,notepadqq/CodeMirror,grzegorzmazur/CodeMirror,notepadqq/CodeMirror,pabloferz/CodeMirror,dperetti/CodeMirror,mtaran-google/CodeMirror,schanzer/CodeMirror,jkaplon/CodeMirror,crazy4chrissi/CodeMirror,pabloferz/CodeMirror,SidPresse/CodeMirror,crazy4chrissi/CodeMirror,namin/CodeMirror,jayaprabhakar/CodeMirror,kerabromsmu/CodeMirror,namin/CodeMirror,thomasjm/CodeMirror,codio/CodeMirror,jayaprabhakar/CodeMirror,ejgallego/CodeMirror,SidPresse/CodeMirror,codio/CodeMirror,jkaplon/CodeMirror,hackmdio/CodeMirror,mtaran-google/CodeMirror,mtaran-google/CodeMirror,kerabromsmu/CodeMirror,namin/CodeMirror,jayaprabhakar/CodeMirror,hackmdio/CodeMirror,ficristo/CodeMirror,wingify/CodeMirror,ejgallego/CodeMirror