out_kinesis_firehose: add missing cast
@@ -204,7 +204,7 @@ static int cb_firehose_init(struct flb_output_instance *ins,
ctx->aws_provider = flb_sts_provider_create(config,
ctx->sts_tls,
ctx->base_aws_provider,
- ctx->external_id,
+ (char *) ctx->external_id,
(char *) ctx->role_arn,
session_name,
(char *) ctx->region,
