CMake // Fixed issue with static build for MSVC2010

Fixed issue with static build for MSVC2010.
The issue was raised in following thread http://curl.haxx.se/mail/lib-2013-07/0046.html

After some investigation I've discovered known issue http://public.kitware.com/Bug/view.php?id=11240
When .rc file is linked to static lib it fails with following linker error 

LINK : warning LNK4068: /MACHINE not specified; defaulting to X86
file.obj : fatal error LNK1112: module machine type 'x64' conflicts with target machine type 'X86' 

changes 8c5e5ec will address this issue.
tested with both x86/x64 targets