configure: Include net/if.h to check for netinet headers on Solaris.

configure

diff --git a/configure b/configure
index f2bf40e..6fd07c8 100755
--- a/configure
+++ b/configure
Binary files differ

configure.ac

diff --git a/configure.ac b/configure.ac
index fe71343..8b78efe 100644
--- a/configure.ac
+++ b/configure.ac
@@ -408,6 +408,9 @@
      #ifdef HAVE_NETINET_IN_SYSTM_H
      # include <netinet/in_systm.h>
      #endif
+     #ifdef HAVE_NET_IF_H
+     # include <net/if.h>
+     #endif
      #ifdef HAVE_NETINET_IP_H
      # include <netinet/ip.h>
      #endif])