Update re2 URL.

Update re2 URL.

The old URL is just a redirect to the new URL, so update to the new.
This also updates the license description to pass presubmit.

BUG=chromium:476190
Committed: https://crrev.com/4e4c9c0c6cadd233c60bc33136aeecaf194a5847
Cr-Commit-Position: refs/heads/master@{#353097}

[bungeman-chromium, 2015-10-08 17:47:46]

bungeman@chromium.org changed reviewers:
+ tfarina@chromium.org, thakis@chromium.org

[Nico, 2015-10-08 17:48:28]

lgtm, thanks :-)

[bungeman-chromium, 2015-10-08 17:53:41]

The CQ bit was checked by bungeman@chromium.org

[tfarina, 2015-10-08 17:55:30]

lgtm, thanks.

[commit-bot: I haz the power, 2015-10-08 17:58:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1395563004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1395563004/1

[commit-bot: I haz the power, 2015-10-08 18:31:31]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-08 18:32:37]

Patchset 1 (id:??) landed as
https://crrev.com/4e4c9c0c6cadd233c60bc33136aeecaf194a5847
Cr-Commit-Position: refs/heads/master@{#353097}