fix missing standard includes

These were a problem only if arch.h does not include them.

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

src/apps/http/altcp_proxyconnect.c

@@ -51,6 +51,8 @@
 #include "lwip/mem.h"
 #include "lwip/init.h"
 
+#include <stdio.h>
+
 /** This string is passed in the HTTP header as "User-Agent: " */
 #ifndef ALTCP_PROXYCONNECT_CLIENT_AGENT
 #define ALTCP_PROXYCONNECT_CLIENT_AGENT "lwIP/" LWIP_VERSION_STRING " (http://savannah.nongnu.org/projects/lwip)"

src/apps/http/http_client.c

@@ -55,6 +55,7 @@
 #include "lwip/init.h"
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #if LWIP_TCP && LWIP_CALLBACK_API