[BUILD] types/proxy.h: reorder a few includes.

OpenBSD is very sensible on the order of includes :
sys/types.h, sys/socket.h, netinet/in.h and arpa/inet.h must be
included in this exact order.

include/types/proxy.h

@@ -22,9 +22,10 @@
 #ifndef _TYPES_PROXY_H
 #define _TYPES_PROXY_H
 
+#include <sys/types.h>
+#include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
-#include <sys/socket.h>
 
 #include <common/appsession.h>
 #include <common/chtbl.h>