doc: fixed formatting issue in cli docs

Removed some bad escape characters

Fixes: nodejs#13805

Author: Chris Young

doc/api/cli.md

@@ -512,7 +512,7 @@ added: v6.11.0
 
 Load an OpenSSL configuration file on startup. Among other uses, this can be
 used to enable FIPS-compliant crypto if Node.js is built with `./configure
-\-\-openssl\-fips`.
+--openssl-fips`.
 
 If the [`--openssl-config`][] command line option is used, the environment
 variable is ignored.