Removed example, and added default value to content_type()

Signed-off-by: Zsolt Gyulai (zgyulai) <[email protected]>

Author: zsoltgyulai94

doc/_admin-guide/070_Destinations/225_Amazon-s3/000_amazon_s3_options.md

@@ -55,24 +55,10 @@ If an invalid value is configured, the default is used.
 ## content-type()
 
 |Type:|   string|
-|Default:|      |
+|Default:|      `application/octet-stream`|
 
 *Description:* This option allows the user to change the displayed content type of the log messages.
 
-### Example: content-type() applied in an S3 destination
-
-```config
-s3(
-	url("http://localhost:9000")
-	bucket("testbucket")
-	object_key("testobject")
-	access_key("<ACCESS_KEY_ID>")
-	secret_key("<SECRET_ACCESS_KEY>")
-	content_type("text/plain")
-	use_checksum("when_required")
-);
-```
-
 ## compression()
 
 |Type:|   boolean|