up the gate window to 20 to help get through backlog
up the gate window to 20 to help get through backlog

we're actually at a relatively low failure rate in the gate, with
lots of resources, and a big backlog. Let's increase this to 20
to help process.

Change-Id: I37d6ae9f4c251d0a3821a70180edbfba81237000

noorul/os-project-config,anbangr/osci-project-config,noorul/os-project-config,open-switch/infra_project-config,open-switch/infra_project-config,coolsvap/project-config,coolsvap/project-config,Tesora/tesora-project-config,osrg/project-config,openstack-infra/project-config,citrix-openstack/project-config,Tesora/tesora-project-config,openstack-infra/project-config,dongwenjuan/project-config,citrix-openstack/project-config,anbangr/osci-project-config,osrg/project-config,dongwenjuan/project-config