client: show json state file when there is invalid data
client: show json state file when there is invalid data

Bug: 1101481
Change-Id: I4a00edc0478d71771b87a3e6c86362b63ffcf2fb
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-py/+/2277556
Commit-Queue: Ye Kuang <1cd89f22f3967fc3dcb883b53940be4b98ec483f@google.com>
Reviewed-by: Ye Kuang <1cd89f22f3967fc3dcb883b53940be4b98ec483f@google.com>
Auto-Submit: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>

luci/luci-py,luci/luci-py,luci/luci-py,luci/luci-py