sethostname: avoid including unistd.h to duck for warnings

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#define GETHOSTNAME_ENV_VAR "CURL_GETHOSTNAME"

/*

 * we force our own host name, in order to make some tests machine independent

 *

 * Since some systems think this prototype doesn't match the system provided

 * function, we AVOID including unistd.h or other headers that may include the

 * original prototype!

 */

int gethostname(char *name, size_t namelen) {

int gethostname(char *name, size_t namelen)

{

  const char *force_hostname = getenv(GETHOSTNAME_ENV_VAR);

  if(force_hostname) {

    strncpy(name, force_hostname, namelen);