[Spellcheck] Switch to https download

[Spellcheck] Switch to https download

Download dictionaries via https instead of http, preventing MITM
attacks against dicts. Plus, HTTPS 4 LYFE!

BUG=479162
Committed: https://crrev.com/6703b5a51cedaa0ead73047d969f8c04362f51f1
Cr-Commit-Position: refs/heads/master@{#326954}

[groby-ooo-7-16, 2015-04-23 02:15:07]

groby@chromium.org changed reviewers:
+ rouslan@chromium.org

[groby-ooo-7-16, 2015-04-23 02:16:07]

rouslan, PTAL - also, if you could give this a try on your machine to see if
dicts still download. OSX is happily excluded, so I can't test right now.

[please use gerrit instead, 2015-04-23 15:47:49]

On 2015/04/23 02:16:07, groby wrote:
> rouslan, PTAL - also, if you could give this a try on your machine to see if
> dicts still download. OSX is happily excluded, so I can't test right now.

Verified that it works.

LGTM.

[groby-ooo-7-16, 2015-04-25 01:05:11]

The CQ bit was checked by groby@chromium.org

[commit-bot: I haz the power, 2015-04-25 01:05:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1056103005/1

[commit-bot: I haz the power, 2015-04-25 02:46:22]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-25 02:47:00]

Patchset 1 (id:??) landed as
https://crrev.com/6703b5a51cedaa0ead73047d969f8c04362f51f1
Cr-Commit-Position: refs/heads/master@{#326954}