Actually fix libosxutil includes, as many times as I'd like to belive using...

Actually fix libosxutil includes, as many times as I'd like to belive using 'diff' to transfer from a working copy to a non-working copy is the safest I always endup convincing myself that it's impossible to screw-up a _two_ line patch.

Originally committed to SVN as r3121.

aegisub/src/subtitles_provider_libass.cpp

@@ -51,8 +51,8 @@
 extern "C" {
 #include "libosxutil/libosxutil.h"
 #include <sys/param.h>
-#endif
 }
+#endif
 
 ///////////////
 // Constructor