updated toc to point to the renamed file

Author: spelluru

articles/event-hubs/TOC.yml

@@ -245,7 +245,7 @@
         - name: Replicate data from a Kafka cluster to Event Hubs
           items:
           - name: Using Apache Kafka Mirror Maker 2
-            href: event-hubs-kafka-mirror-maker-2-tutorial.md
+            href: event-hubs-kafka-mirrormaker-2-tutorial.md
           - name: Using Apache Kafka Mirror Maker 1
             href: event-hubs-kafka-mirror-maker-tutorial.md
         - name: Connect Apache Spark to an event hub