Update the Estonian workaround comments.

Target date for removal of the workaround is 6 months.

BUG=532048

Change-Id: I402f75e46736936725575559cd8eb194115ab0df
Reviewed-on: https://boringssl-review.googlesource.com/5910
Reviewed-by: Adam Langley <agl@google.com>
3 files changed