Don't email autolink if only period is at end

[kivikakk]

See test case:

  def test_non_emails_ending_in_periods
    assert_linked "abc/def@ghi.", "abc/def@ghi."
    assert_linked "abc/def@ghi. ", "abc/def@ghi. "
    assert_linked "abc/def@ghi. x", "abc/def@ghi. x"
    assert_linked "abc/def@ghi.< x", "abc/def@ghi.< x"
    assert_linked "abc/<a href=\"mailto:def@ghi.x\">def@ghi.x</a>", "abc/def@ghi.x"
    assert_linked "abc/<a href=\"mailto:def@ghi.x\">def@ghi.x</a>. a", "abc/def@ghi.x. a"
  end

[vmg]

Ah this is a good fix.