kafka-c: remove remaining references of the removed properties-file() option (#257)

Author: HofiOne

_includes/doc/admin-guide/notes/kafka-c.md

@@ -21,8 +21,6 @@ You can specify multiple, comma-separated addresses, demonstrated in the followi
 bootstrap-servers("127.0.0.1:2525,remote-server-hostname:6464")
 ```
 
-{% include doc/admin-guide/notes/kafka-c.md %}
-
 {% include doc/admin-guide/options/batch-lines.md %}
 
 **NOTE:** The {{ site.product.short_name }} configuration accepts this option with
@@ -82,8 +80,6 @@ The programming language accepts this option for better compatibility.
 
 *Description:* You can use this option to set the properties of the kafka producer.
 
-{% include doc/admin-guide/notes/kafka-c.md %}
-
 The {{ site.product.short_name }} kafka destination supports all properties of the
 official Kafka producer. For details, see the librdkafka documentation.
 
@@ -176,8 +172,6 @@ client about the amount of messages sent since the last poll-timeout ().
 In case of multithreading, the first {{ site.product.short_name }} worker is responsible for
 poll-timeout().
 
-{% include doc/admin-guide/notes/kafka-c.md %}
-
 {% include doc/admin-guide/options/retries.md %}
 
 {% include doc/admin-guide/options/send-time-zone.md %}