Fix: enable DPI-awareness for MINGW builds

src/os/windows/ottdres.rc.in

@@ -14,7 +14,7 @@
 #define APSTUDIO_HIDDEN_SYMBOLS
 #include "windows.h"
 #undef APSTUDIO_HIDDEN_SYMBOLS
-#ifdef MSVC
+#ifndef __MINGW32__
 #include "winres.h"
 #else
 #define IDC_STATIC              (-1)     // all static controls
@@ -117,5 +117,9 @@ END
 
 #endif    // !_MAC
 
+#ifdef __MINGW32__
+1 24 "..\\..\\..\\projects\\dpi_aware.manifest"
+#endif
+
 #endif    // Neutral (Default) resources
 /////////////////////////////////////////////////////////////////////////////