precision on email_filter
precision on email_filter

The filtering regexp should not allow greedy matchers (such as .*) but
use non greedy ones (such as .*?).  One want to escape dots as well.

Additionally, whenever one want to add several emails, he should use a
YAML list.

Change-Id: I9deea0893151358ddde9b1ec5a40c322c45d7ff2
Reviewed-on: https://review.openstack.org/18350
Reviewed-by: James E. Blair <e81a02a9d6405977f63a769d9f6ec8ed9d924325@inaugust.com>
Approved: James E. Blair <e81a02a9d6405977f63a769d9f6ec8ed9d924325@inaugust.com>
Tested-by: Jenkins

gooddata/zuul,devdattakulkarni/zuul_messaging,gooddata/zuul,wikimedia/integration-zuul,devdattakulkarni/zuul_messaging,wikimedia/integration-zuul,wikimedia/integration-zuul,devdattakulkarni/zuul_messaging,gooddata/zuul,gooddata/zuul,gooddata/zuul,wikimedia/integration-zuul