[fakecas] Change fakecase to use dynamic port by default
[fakecas] Change fakecase to use dynamic port by default

Bug: 1255535
Change-Id: I1661675c6a429b40b424e731b11751b2db14975d
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/3276073
Commit-Queue: Junji Watanabe <aaef61ef98ffea505db831f310be2a0eb8492537@google.com>
Commit-Queue: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
Auto-Submit: Junji Watanabe <aaef61ef98ffea505db831f310be2a0eb8492537@google.com>
Reviewed-by: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go