[Autofill Assistant] Added log message for the script server domain.

We are seeing frequent issues where phones are connecting to the wrong script server domain, leading to permission errors and abort. This log message should help us in debugging those issues.

Bug: 806868
Change-Id: I49c469d33e924c0cb65db2398c686b6930313098
Reviewed-on: https://chromium-review.googlesource.com/c/1482961
Reviewed-by: Stephane Zermatten <szermatt@chromium.org>
Commit-Queue: Clemens Arbesser <arbesser@google.com>
Cr-Commit-Position: refs/heads/master@{#634694}
1 file changed