update slug so that it is unique

Author: Blargian

docs/integrations/data-ingestion/kafka/confluent/confluent-cloud.md

@@ -1,7 +1,7 @@
 ---
 sidebar_label: 'Kafka Connector Sink on Confluent Cloud'
 sidebar_position: 2
-slug: /integrations/kafka/cloud/confluent/custom-connector
+slug: /integrations/kafka/cloud/confluent/integrate-custom-connector
 description: 'Guide to using the fully managed ClickHouse Connector Sinkon Confluent Cloud'
 title: 'Integrating Confluent Cloud with ClickHouse'
 keywords: ['Kafka', 'Confluent Cloud']