MinGW: correct compiler defines

It seems MinGW uses __MINGW32_MAJOR_VERSION (major before version) for 32 bit,
but __MINGW64_VERSION_MAJOR (version befor major) for 64 bit.

src/main.c

@@ -847,13 +847,13 @@ static void start_civetweb(int argc, char *argv[])
 		        (unsigned)__MINGW64_VERSION_MINOR);
 		fprintf(stdout,
 		        "MinGW32: %u.%u\n",
-		        (unsigned)__MINGW32_VERSION_MAJOR,
-		        (unsigned)__MINGW32_VERSION_MINOR);
+		        (unsigned)__MINGW32_MAJOR_VERSION,
+		        (unsigned)__MINGW32_MINOR_VERSION);
 #elif defined(__MINGW32__)
 		fprintf(stdout,
 		        "MinGW32: %u.%u\n",
-		        (unsigned)__MINGW32_VERSION_MAJOR,
-		        (unsigned)__MINGW32_VERSION_MINOR);
+		        (unsigned)__MINGW32_MAJOR_VERSION,
+		        (unsigned)__MINGW32_MINOR_VERSION);
 #elif defined(__clang__)
 		fprintf(stdout,
 		        "clang: %u.%u.%u (%s)\n",