gluster: Map status In Progress to Job status Started

Gluster tasks return a status "In progress"
for tasks that are currently running.
This needs to be mapped to JobExecutionStatus.STARTED
for monitoring to work correctly

Change-Id: I55c657cb8142b4248f20f1789317726acbdb0852
Signed-off-by: Sahina Bose <sabose@redhat.com>