Can't edit lines in writeable books

Can't edit lines in writeable books

You are writing a book. You full a page. But the first line contains an orthographic error. You need to remove ALL lines to only edit the first one.

Steps to Reproduce:
1. Write a full page of a book
2. Try to edit the first line
3. You need to remove all lines only to fix only 1 word!

Thanks Mojang, try to fix it!

PS: Sorry about my english, im from spain...