update jwt guard event message

runtime/guard-jwt/src/main/java/io/aklivity/zilla/runtime/guard/jwt/internal/JwtEventFormatter.java

@@ -47,7 +47,7 @@ public String format(
         case AUTHORIZATION_FAILED:
         {
             JwtAuthorizationFailedExFW ex = extension.authorizationFailed();
-            result = String.format("%s", identity(ex.identity()));
+            result = String.format("No active session found for token identity (%s).", identity(ex.identity()));
             break;
         }
         }

specs/guard-jwt.spec/src/main/scripts/io/aklivity/zilla/specs/guard/jwt/config/event.yaml

@@ -24,7 +24,7 @@ telemetry:
           - qname: test.net0
             id: guard.jwt.authorization.failed
             name: GUARD_JWT_AUTHORIZATION_FAILED
-            message: user
+            message: No active session found for token identity (user).
 guards:
   jwt0:
     type: jwt