Don't modify the driver signature on the web

(cherry picked from commit 95dafa2bcd90ee20a1103a9b6b2456e8b7455f8f)

src/joystick/emscripten/SDL_sysjoystick.c

@@ -182,10 +182,6 @@ static EM_BOOL Emscripten_JoyStickConnected(int eventType, const EmscriptenGamep
         item->guid.data[15] = os_id;
     }
 
-    if (is_xinput) {
-        item->guid.data[14] = 'x'; // See SDL_IsJoystickXInput
-    }
-
     item->mapping = SDL_strdup(gamepadEvent->mapping);
     if (!item->mapping) {
         SDL_free(item->name);