Remove old msc ver. Freecad 0.20 require 64 bit and windows 7 or higher. For this reason, msc libraries less than 1800 will no longer be used. (#7036)

* remove msc<1800

src/Main/MainGui.cpp

@@ -160,11 +160,6 @@ int main( int argc, char ** argv )
     }
 #endif
 
-#if defined(_MSC_VER) && _MSC_VER <= 1800
-    // See InterpreterSingleton::init
-    Redirection out(stdout), err(stderr), inp(stdin);
-#endif
-
     // Name and Version of the Application
     App::Application::Config()["ExeName"] = "FreeCAD";
     App::Application::Config()["ExeVendor"] = "FreeCAD";