chore: update Py2 support msg to reflect passage of time (#59)

Source-Author: Dan O'Meara <danom@google.com>
Source-Date: Mon Jun 29 13:20:01 2020 -0700
Source-Repo: googleapis/synthtool
Source-Sha: 303271797a360f8a439203413f13a160f2f5b3b4
Source-Link: https://github.com/googleapis/synthtool/commit/303271797a360f8a439203413f13a160f2f5b3b4