Fix using RegisterHotKey() with negative IDs in wxMSW.

This was broken due to a wrong cast from WPARAM (i.e. 32 bit unsigned int in
Win32) value containing the ID to WORD (i.e. 16 bit unsigned short) which
truncated the ID value.

Notice that MSDN documents the requirement for the IDs to be positive, but
negative IDs seem to work, at least with Windows 7, after this fix.

Closes #16880.

docs/changes.txt

@@ -609,6 +609,7 @@ wxMSW:
 - Fix disabling submenu items in the menus (Artur Wieczorek).
 - Fix wxEVT_TREE_STATE_IMAGE_CLICK generation (Antal).
 - Fix wxDV_ROW_LINES in horizontally scrolled wxDataViewCtrl.
+- Fix RegisterHotKey() with negative IDs (troelsk).
 
 wxOSX:
 

src/msw/window.cpp

@@ -3245,7 +3245,7 @@ wxWindowMSW::MSWHandleMessage(WXLRESULT *result,
 
 #if wxUSE_HOTKEY
         case WM_HOTKEY:
-            processed = HandleHotKey((WORD)wParam, lParam);
+            processed = HandleHotKey(wParam, lParam);
             break;
 #endif // wxUSE_HOTKEY