Windows: Added a #define missing from some versions of the Windows 10 SDK

modules/juce_gui_basics/native/juce_win32_Windowing.cpp

@@ -269,6 +269,12 @@ extern void* getUser32Function (const char*);
  #define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 ((DPI_AWARENESS_CONTEXT) - 4)
 #endif
 
+// Some versions of the Windows 10 SDK define _DPI_AWARENESS_CONTEXTS_ but not
+// DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
+#ifndef DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
+ #define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 ((DPI_AWARENESS_CONTEXT) - 4)
+#endif
+
 //==============================================================================
 typedef BOOL (WINAPI* RegisterTouchWindowFunc)   (HWND, ULONG);
 typedef BOOL (WINAPI* GetTouchInputInfoFunc)     (HTOUCHINPUT, UINT, TOUCHINPUT*, int);