chore: update config example

cchenggit · cchenggit · commit beec76221962 · 2025-10-30T20:55:01.000+08:00
diff --git a/webhookx.sample.yml b/webhookx.sample.yml
@@ -33,6 +33,7 @@ sources:
     plugins:
       - name: "jsonschema-validator"
         config:
+          draft_version: 6
           schemas:
             charge.succeeded:
               schema: |
