Actually update win_toolchain to 2019 (14.24.28314)

Change-Id: Ieb695288f2643a2959b76777d02af67ac49c245d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/261544
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2 files changed