test: Add missing socket errno in test_util.c

According to 21116, it seems to be needed for Wheezy Raspbian build. Also,
manpage of socket(2) does confirm that this errno value should be catched as
well in case of no support from the OS of IPv4 or/and IPv6.

Fixes #21116

Signed-off-by: David Goulet <dgoulet@torproject.org>

changes/bug21116

@@ -0,0 +1,3 @@
+  o Minor bugfixes (test):
+    - Fix Raspbian build missing socket errno in test util. Fixes bug 21116.;
+      bugfix on tor-0.2.8.2. Patch by "hein".

src/test/test_util.c

@@ -5091,7 +5091,8 @@ test_util_socket(void *arg)
 
   fd1 = tor_open_socket_with_extensions(domain, SOCK_STREAM, 0, 0, 0);
   int err = tor_socket_errno(fd1);
-  if (fd1 < 0 && err == SOCK_ERRNO(EPROTONOSUPPORT)) {
+  if (fd1 < 0 && (err == SOCK_ERRNO(EPROTONOSUPPORT) ||
+                  err == SOCK_ERRNO(EAFNOSUPPORT))) {
     /* Assume we're on an IPv4-only or IPv6-only system, and give up now. */
     goto done;
   }