fix incorrect link

Author: c2bo

draft-ietf-oauth-attestation-based-client-auth.md

@@ -310,7 +310,7 @@ It is RECOMMENDED that the authorization server validate the Client Attestation
 
 To validate an HTTP request which contains the client attestation headers, the receiving server MUST ensure the following with regard to a received HTTP request:
 
-1. There is precisely one OAuth-Client-Attestation HTTP request header field, where its value is a single well-formed JWT conforming to the syntax outlined in []{client-attestation-jwt}.
+1. There is precisely one OAuth-Client-Attestation HTTP request header field, where its value is a single well-formed JWT conforming to the syntax outlined in [](client-attestation-jwt).
 2. There is precisely one OAuth-Client-Attestation-PoP HTTP request header field, where its value is a single well-formed JWT conforming to the syntax outlined in [](client-attestation-pop-jwt).
 3. The signature of the Client Attestation PoP JWT obtained from the OAuth-Client-Attestation-PoP HTTP header verifies with the Client Instance Key contained in the `cnf` claim of the Client Attestation JWT obtained from the OAuth-Client-Attestation HTTP header.