compile fix on mingw: mingw does not define _MSC_VER.
svn:r9682
#define WIN32_WINNT 0x400
#define _WIN32_WINNT 0x400
#define WIN32_LEAN_AND_MEAN
-#if (_MSC_VER <= 1300)
+#if defined(_MSC_VER) && (_MSC_VER <= 1300)
#include <winsock.h>
#else
#include <winsock2.h>
#ifdef HAVE_STRTOULL
r = (uint64_t)strtoull(s, &endptr, base);
#elif defined(MS_WINDOWS)
-#if _MSC_VER < 1300
+#if defined(_MSC_VER) && _MSC_VER < 1300
tor_assert(base <= 10);
r = (uint64_t)_atoi64(s);
endptr = (char*)s;
#endif
#ifdef MS_WINDOWS
-#if (_MSC_VER <= 1300)
+#if defined(_MSC_VER) && (_MSC_VER <= 1300)
#include <winsock.h>
#else
#include <winsock2.h>