fix misplaced parenthesis

Author: Ashe Connor

README.md

@@ -168,8 +168,8 @@ By default, the library will scrub raw HTML and potentially dangerous links
 _opposite_ of the upstream [`cmark`](https://github.com/CommonMark/cmark)
 library, a change introduced in `cmark-gfm` in version `0.28.3.gfm.18`.
 
-To allow these, use the option `CMARK_OPT_UNSAFE` (or `--unsafe`) with the
-command line program. If doing so, we recommend you use a HTML sanitizer
+To allow these, use the option `CMARK_OPT_UNSAFE` (or `--unsafe` with the
+command line program). If doing so, we recommend you use a HTML sanitizer
 specific to your needs to protect against [XSS
 attacks](http://en.wikipedia.org/wiki/Cross-site_scripting).