updated for version 7.3.376

Problem:    Win32: Toolbar repainting does not work when the mouse pointer
            hovers over a button.
Solution:   Call DefWindowProc() when not hanlding an event. (Sergiu Dotenco)

src/gui_w32.c

@@ -1101,7 +1101,7 @@ _WndProc(
 	return MyWindowProc(hwnd, uMsg, wParam, lParam);
     }
 
-    return 1;
+    return DefWindowProc(hwnd, uMsg, wParam, lParam);
 }
 
 /*