MINOR: tproxy: add support for OpenBSD

OpenBSD uses (SOL_SOCKET, SO_BINDANY) to enable transparent
proxy on a socket.

This patch adds support for the relevant setsockopt() calls.
diff --git a/include/common/compat.h b/include/common/compat.h
index efc2a6e..0085a3a 100644
--- a/include/common/compat.h
+++ b/include/common/compat.h
@@ -96,6 +96,7 @@
 #if defined(IP_FREEBIND)       \
  || defined(IP_BINDANY)        \
  || defined(IPV6_BINDANY)      \
+ || defined(SO_BINDANY)        \
  || defined(IP_TRANSPARENT)    \
  || defined(IPV6_TRANSPARENT)
 #define CONFIG_HAP_TRANSPARENT