out_kinesis_streams: Do not include <unistd.h> on Windows
MSVC does not provide <unistd.h> as part of C stdlib. Add an ifdef
block to the #include line to avoid compilation error.
#include <msgpack.h>
#include <string.h>
#include <stdio.h>
-#include <unistd.h>
#include <stdlib.h>
+#ifndef FLB_SYSTEM_WINDOWS
+#include <unistd.h>
+#endif
+
#include "kinesis_api.h"
#define ERR_CODE_EXCEEDED_THROUGHPUT "ProvisionedThroughputExceededException"
