9-regular-expressions/14-regexp-lookahead-lookbehind/article.md 内容删改

[Serious54088]

目标章节：9-regular-expressions/14-regexp-lookahead-lookbehind/article.md

”捕获组“小节，删减最后两行（参考英文版）。

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[Serious54088]

This is an automatic reply, confirming that your email was received. I will reply as soon as possible. Thank you!