Typo of ' instead of ` (#50767)

Author: seanstory

x-pack/docs/en/security/authentication/saml-guide.asciidoc

@@ -924,7 +924,7 @@ POST /_security/saml/prepare
 --------------------------------------------------
 
 . Handle the response from `/_security/saml/prepare`. The response from {es} will contain 3 parameters:
-  `redirect`, `realm' and `id`. The custom web application would need to store the value for `id`
+  `redirect`, `realm` and `id`. The custom web application would need to store the value for `id`
  in the user's session (client side in a cookie or server side if session information is
 persisted this way). It must also redirect the user's browser to the URL that  was returned in the 
   `redirect` parameter. The `id` value should not be disregarded as it is used as a nonce in SAML in