Fix: [MinGW] Set minimum OS version to Windows XP (#9135)

(cherry picked from commit 356bbbb90a)

src/network/network_chat_gui.cpp

@@ -7,9 +7,6 @@
 
 /** @file network_chat_gui.cpp GUI for handling chat messages. */
 
-#include <stdarg.h> /* va_list */
-#include <deque>
-
 #include "../stdafx.h"
 #include "../strings_func.h"
 #include "../blitter/factory.hpp"
@@ -28,6 +25,9 @@
 
 #include "table/strings.h"
 
+#include <stdarg.h> /* va_list */
+#include <deque>
+
 #include "../safeguards.h"
 
 /** The draw buffer must be able to contain the chat message, client name and the "[All]" message,