"Increases delta of start_time when collecting OpenStack metrics"

This reverts commit f8d6f160a42e66ac5c59ff01fd338053d110ee42.

Change-Id: I920dfa78faae4827db31298f60552e1e49a87eb9
diff --git a/osm_mon/collector/collectors/openstack.py b/osm_mon/collector/collectors/openstack.py
index 395d607..30bab0c 100644
--- a/osm_mon/collector/collectors/openstack.py
+++ b/osm_mon/collector/collectors/openstack.py
@@ -99,7 +99,8 @@
                 for param in vdu['monitoring-param']:
                     metric_name = param['nfvi-metric']
                     gnocchi_metric_name = METRIC_MAPPINGS[metric_name]
-                    start_date = datetime.datetime.now() - datetime.timedelta(seconds=self.granularity)
+                    delta = 10 * self.granularity
+                    start_date = datetime.datetime.now() - datetime.timedelta(seconds=delta)
                     resource_id = self._get_resource_uuid(nsr_id, vnf_member_index, vdur['name'])
                     try:
                         measures = self.gnocchi_client.metric.get_measures(gnocchi_metric_name,