(doc) fix SSL cert generating command error
//
// ```bash
// openssl req -x509 -newkey rsa:4096 -nodes -keyout localhost.key -out localhost.crt -days 3650
-// openssl pkcs12 -export -out identity.p12 -inkey localhost.key -in localhost.crt -password mypass
+// openssl pkcs12 -export -out identity.p12 -inkey localhost.key -in localhost.crt -password pass:mypass
//
// ```
