example/webclient : Fix compilation error without TLS option
This commit is to fix compilation error on webclient example without TLS
1. add (char *) cast in front of malloc
webclient_main.c: In function 'webclient_init_request':
webclient_main.c:245:21:
error: assignment makes pointer from integer without a cast [-Werror]
request->entity = malloc(t);
2. add stdlib.h
webclient_main.c:237: undefined reference to `atoi'
webclient_main.c:239: undefined reference to `atoi'
webclient_main.c:243: undefined reference to `atoi'
Change-Id: I85859de77349dcd922237b3737f7039873913e20
Signed-off-by: Jin-Seong Kim <jseong82.kim@samsung.com>