Fixed potential build issue

(Doesn't compile when I run build modules, but does compile when I run the example without this fix)

tiff.mod/source.bmx

@@ -24,6 +24,7 @@ SuperStrict
 Import "config/*.h"
 Import "tiff/libtiff/*.h"
 Import "../jpg.mod/libjpeg/*.h"
+Import "../../archive.mod/zlib.mod/zlib/*.h"
 
 Import "glue.c"