inseng: Exclude unused header

[Andrew Talbot]

Changelog:
    inseng: Exclude unused header.

diff -urN a/dlls/inseng/inseng_main.c b/dlls/inseng/inseng_main.c
--- a/dlls/inseng/inseng_main.c	2006-11-13 12:49:43.000000000 +0000
+++ b/dlls/inseng/inseng_main.c	2007-05-07 12:39:09.000000000 +0100
@@ -27,7 +27,6 @@
 #include "windef.h"
 #include "winbase.h"
 #include "winuser.h"
-#include "winreg.h"
 #include "ole2.h"
 #include "initguid.h"