subsys/net/lib/http: Set feature macro as required

This file uses strnlen() but the C library
is not require to expose its prototype unless
_POSIX_C_SOURCE is defined.
So let's define it to avoid an implicit function
declaration warning.

(cherry picked from commit f131964)

Original-Signed-off-by: Alberto Escolar Piedras <[email protected]>
GitOrigin-RevId: f131964
Change-Id: I64d37c7cf14a15a72b7b3f79ede789e02f5587ca
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5653340
Reviewed-by: Ting Shen <[email protected]>
Tested-by: ChromeOS Prod (Robot) <[email protected]>
Tested-by: Ting Shen <[email protected]>
Commit-Queue: Ting Shen <[email protected]>

Author: aescolar

subsys/net/lib/http/http_server_http1.c

@@ -5,6 +5,9 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#undef _POSIX_C_SOURCE
+#define _POSIX_C_SOURCE 200809L /* Required for strnlen() */
+
 #include <errno.h>
 #include <stdbool.h>
 #include <stdio.h>