aws_util: fix type of extra_user_agent

Signed-off-by: Takahiro Yamashita <[email protected]>

Author: nokute78

include/fluent-bit/flb_aws_util.h

@@ -79,7 +79,7 @@ struct flb_aws_client {
     int port;
     char *proxy;
     int flags;
-    flb_sds_t *extra_user_agent;
+    flb_sds_t extra_user_agent;
     int free_user_agent;
 
     /*