Fix typo in digest.adoc

Closes gh-10304

docs/manual/src/docs/asciidoc/_includes/servlet/authentication/unpwd/digest.adoc

@@ -34,7 +34,7 @@ key:              A private key to prevent modification of the nonce token
 ----
 ====
 
-You will need to ensure you <<authentication-password-storage-configuration,configure>> insecure plain text <<authentication-password-storage,Password Storage>> using NoOpPasswordEncoder`.
+You will need to ensure you <<authentication-password-storage-configuration,configure>> insecure plain text <<authentication-password-storage,Password Storage>> using `NoOpPasswordEncoder`.
 The following provides an example of configuring Digest Authentication with Java Configuration:
 
 .Digest Authentication