fix for typing on empty line in firefox
fix for typing on empty line in firefox

really we were being sloppy and chrome was being tolerant

tim-mc/quill,quilljs/quill,voxmedia/quill,tim-mc/quill,willrowe/quill,fraywing/quill,willrowe/quill,voxmedia/quill,fraywing/quill,sferoze/quilljs,quilljs/quill,quilljs/quill,willrowe/quill,sferoze/quilljs,sferoze/quilljs,sferoze/quilljs,voxmedia/quill