Increase pypi mirror job timeouts.

Raise the pypi mirror job timeout from the default 30 minutes to 45.
At best the jobs take just under 20 minutes to complete, but
variability in network performance is frequently pushing them beyond
30 thus causing premature termination and failure.

Change-Id: I21718e7e44f91827f1648988d10c62f0ad69e707
Reviewed-on: https://review.openstack.org/27928
Reviewed-by: James E. Blair <corvus@inaugust.com>
Approved: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins