Boost 1.52 no longer supports Boost.Filesystem v2 -- don't request.

Instead of compatibility mode, #defining BOOST_FILESYSTEM_VERSION to 2 only
gets you a compile error these days.

indra/llcommon/linden_common.h

@@ -59,8 +59,4 @@
 #include "llerror.h"
 #include "llfile.h"
 
-// Boost 1.45 had version 2 as the default for the filesystem library,
-// 1.48 has version 3 as the default.  Keep compatibility for now.
-#define BOOST_FILESYSTEM_VERSION		2
-
 #endif