Fix install-sysroot.py script not working behind proxy.

Fix install-sysroot.py script not working behind proxy.

This is a regression from https://codereview.chromium.org/2538833006.

urllib is usually pretty flaky with reading env variables to get the
proxy url. urllib2 does a much better job.

BUG=

Committed: https://crrev.com/3d4239679d76e88774843f9dd2a132fcead3b24e
Cr-Commit-Position: refs/heads/master@{#436761}

[darktears, 2016-12-06 20:59:29]

alexis.menard@intel.com changed reviewers:
+ dpranke@chromium.org, thomasanderson@google.com

[darktears, 2016-12-06 20:59:37]

The CQ bit was checked by alexis.menard@intel.com to run a CQ dry run

[commit-bot: I haz the power, 2016-12-06 21:00:06]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Dirk Pranke, 2016-12-06 21:04:33]

lgtm . I'll take your word for it ...

[commit-bot: I haz the power, 2016-12-06 21:21:16]

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

[commit-bot: I haz the power, 2016-12-06 21:21:17]

Dry run: This issue passed the CQ dry run.

[darktears, 2016-12-06 22:11:22]

The CQ bit was checked by alexis.menard@intel.com

[commit-bot: I haz the power, 2016-12-06 22:11:59]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-06 22:30:17]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1481062282708550, "parent_rev":
"932976f8c62b060ccd4ae61d89dce11a214b9f0e", "commit_rev":
"befad33644e011658374e987753f4fd84874ff2c"}

[commit-bot: I haz the power, 2016-12-06 22:30:41]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-06 22:34:05]

Description was changed from

==========
Fix install-sysroot.py script not working behind proxy.

This is a regression from https://codereview.chromium.org/2538833006.

urllib is usually pretty flaky with reading env variables to get the
proxy url. urllib2 does a much better job.

BUG=
==========

to

==========
Fix install-sysroot.py script not working behind proxy.

This is a regression from https://codereview.chromium.org/2538833006.

urllib is usually pretty flaky with reading env variables to get the
proxy url. urllib2 does a much better job.

BUG=

Committed: https://crrev.com/3d4239679d76e88774843f9dd2a132fcead3b24e
Cr-Commit-Position: refs/heads/master@{#436761}
==========

[commit-bot: I haz the power, 2016-12-06 22:34:06]

Patchset 1 (id:??) landed as
https://crrev.com/3d4239679d76e88774843f9dd2a132fcead3b24e
Cr-Commit-Position: refs/heads/master@{#436761}