Merge pull request #1387 from Diapolo/rem_unused_rpcdump

remove dead "using namespace boost::asio;" from rpcdump.cpp

src/rpcdump.cpp

@@ -10,7 +10,6 @@
 
 #define printf OutputDebugStringF
 
-// using namespace boost::asio;
 using namespace json_spirit;
 using namespace std;