Update pthreads-win32 URL.

Update pthreads-win32 URL.

The old URL is an automatic redirect to the new URL, so use the new URL.

BUG=chromium:476190
Committed: https://crrev.com/1a73459491e419d76b8934f4493b642d8a031f55
Cr-Commit-Position: refs/heads/master@{#353537}

[bungeman-chromium, 2015-10-12 14:42:48]

The CQ bit was checked by bungeman@chromium.org to run a CQ dry run

[bungeman-chromium, 2015-10-12 14:42:57]

bungeman@chromium.org changed reviewers:
+ binji@chromium.org

[commit-bot: I haz the power, 2015-10-12 14:43:20]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1401753002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1401753002/1

[commit-bot: I haz the power, 2015-10-12 15:45:33]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-10-12 15:45:34]

Dry run: This issue passed the CQ dry run.

[binji, 2015-10-12 16:51:00]

lgtm

[bungeman-chromium, 2015-10-12 16:55:18]

The CQ bit was checked by bungeman@chromium.org

[commit-bot: I haz the power, 2015-10-12 16:56:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1401753002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1401753002/1

[commit-bot: I haz the power, 2015-10-12 17:05:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-12 17:07:08]

Patchset 1 (id:??) landed as
https://crrev.com/1a73459491e419d76b8934f4493b642d8a031f55
Cr-Commit-Position: refs/heads/master@{#353537}