Remove unnecessary %s in an error message

The %s is not necessary and results in errors like this being returned
to the caller:

{ "error": "Client certificate validation failed: %s", "error_description": "Path does not chain with any of the trust anchors" }

The e.getMessage() is put into the error_description, so the %s is just looks
like a mistake.

Author: jogu

src/main/java/com/authlete/jaxrs/server/api/ClientRegistrationEndpoint.java

@@ -203,7 +203,7 @@ private static void validateCertificate(HttpServletRequest request)
         catch (GeneralSecurityException e)
         {
             throw OBBDCRProcessor.errorResponse(Status.UNAUTHORIZED,
-                    "Client certificate validation failed: %s", e.getMessage());
+                    "Client certificate validation failed", e.getMessage());
         }
     }
 }