adding (empty string) to faq-false-or-none-events.mdx (#9050)

contents/docs/feature-flags/snippets/faq-false-or-none-events.mdx

@@ -1,5 +1,5 @@
-## My `Feature Flag Called` events show `None` or `false` instead of my variant names
+## My `Feature Flag Called` events show `None`, `(empty string)`, or `false` instead of my variant names
 
 The `Feature Flag Response` property is `false` for users who called your feature flag but did not match any of the rollout conditions.
 
-`None` indicates that feature flag is disabled or failed to load. For example, due to network error or something unexpected.
+`None` or `(empty string)` indicates that the feature flag is disabled or failed to load. For example, due to a network error, adblocking, or something unexpected.