Update comment URL of USB document (HID Usage Tables 1.12)

include/SDL_scancode.h

@@ -38,7 +38,7 @@
  *  SDL_Event structure.
  *
  *  The values in this enumeration are based on the USB usage page standard:
- *  http://www.usb.org/developers/hidpage/Hut1_12v2.pdf
+ *  https://www.usb.org/sites/default/files/documents/hut1_12v2.pdf
  */
 typedef enum
 {