[ios] Prevent Xcode codesign in Xcode11.

Bug: 974841
Change-Id: I500a4b0dbb4eda1a7358e2e77b52e6802e111378
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1660151
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#669725}
1 file changed