remove printf redefinition from bitcoinrpc.cpp

- as the redefiniton of printf happens in util.h, which is included in
  bitcoinrpc.cpp, we don't need another redefinition

src/bitcoinrpc.cpp

@@ -11,7 +11,6 @@
 #include "bitcoinrpc.h"
 #include "db.h"
 
-#undef printf
 #include <boost/asio.hpp>
 #include <boost/asio/ip/v6_only.hpp>
 #include <boost/bind.hpp>
@@ -26,8 +25,6 @@
 #include <boost/shared_ptr.hpp>
 #include <list>
 
-#define printf OutputDebugStringF
-
 using namespace std;
 using namespace boost;
 using namespace boost::asio;