build: remove unused file

tests/libtest/hostname.c

-/*****************************************************************************
- *                                  _   _ ____  _
- *  Project                     ___| | | |  _ \| |
- *                             / __| | | | |_) | |
- *                            | (__| |_| |  _ <| |___
- *                             \___|\___/|_| \_\_____|
- *
- */
-
-#include <string.h>
-#include <unistd.h>
-
-#define HOSTNAME "curlhost"
-#define HOSTNAME_LEN sizeof(HOSTNAME)
-
-/* 
- * we force our own host name, in order to make some tests machine independent
- */
-int gethostname(char *name, size_t namelen) {
-  char buff[HOSTNAME_LEN + /* terminating zero */ 1];
-  size_t max = (namelen < HOSTNAME_LEN)
-    ? namelen
-    : HOSTNAME_LEN;
-
-  if(!name || !namelen)
-    return -1;
-
-  strcpy(buff, HOSTNAME);
-  buff[max - 1] = '\0';
-  strcpy(name, buff);
-  return 0;
-};