Revert "Add camel-kafka-connector-0.3.x branch to antora (#402)" (#403)

This reverts commit e498c8cd0aaeddbe8bdbce413511f118ae4c503f.
diff --git a/antora-playbook.yml b/antora-playbook.yml
index 03605e0..bcb26e3 100644
--- a/antora-playbook.yml
+++ b/antora-playbook.yml
@@ -51,9 +51,6 @@
     - url: git@github.com:apache/camel-kafka-connector.git
       branches: master
       start_path: docs
-    - url: git@github.com:apache/camel-kafka-connector.git
-      branches: camel-kafka-connector-0.3.x
-      start_path: docs
     - url: git@github.com:apache/camel-spring-boot.git
       branches: master
       start_path: docs