WinRT: fixed multi-touch bug whereby 2nd, 3rd, etc. fingers weren't moving

Only the first-pressed finger wpuld get reported as having moved (via SDL's
touch APIs).  Subsequently pressed fingers wouldn't report as being moved, even
though the OS was reporting (to SDL) that they had moved.

src/video/winrt/SDL_winrtpointerinput.cpp

@@ -262,7 +262,7 @@ WINRT_ProcessPointerMovedEvent(SDL_Window *window, Windows::UI::Input::PointerPo
 
     if ( ! WINRT_IsTouchEvent(pointerPoint)) {
         SDL_SendMouseMotion(window, 0, 0, (int)windowPoint.X, (int)windowPoint.Y);
-    } else if (pointerPoint->PointerId == WINRT_LeftFingerDown) {
+    } else {
         if (pointerPoint->PointerId == WINRT_LeftFingerDown) {
             SDL_SendMouseMotion(window, 0, 0, (int)windowPoint.X, (int)windowPoint.Y);
         }