[autoroll] Throttle back to 3 CLs every 30 minutes
[autoroll] Throttle back to 3 CLs every 30 minutes

3/10 was still too many.

BUG=skia:697736

Change-Id: Ie926782901c2df9a66b984635653b451e60f6173
Reviewed-on: https://skia-review.googlesource.com/9138
Reviewed-by: Ravi Mistry <9fa2e7438b8cb730f96b74865492597170561628@google.com>
Commit-Queue: Eric Boren <0e499112533c8544f0505ea0d08394fb5ad7d8fa@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot