Fix apache response time casting from us to s

Change-Id: Id23c7a4f858ff36735685c9331517117051795eb
Partial-Fix: PROD-20999
diff --git a/aodh/meta/fluentd.yml b/aodh/meta/fluentd.yml
index e5abc2a..2f77b72 100644
--- a/aodh/meta/fluentd.yml
+++ b/aodh/meta/fluentd.yml
@@ -43,8 +43,9 @@
                 value: INFO
               - name: programname
                 value: aodh-wsgi
+                # Apache logs response time in microseconds
               - name: http_response_time
-                value: ${ record['http_response_time'].to_i/100000.to_f }
+                value: ${ record['http_response_time'].to_i/10**6.to_f }
         match:
           send_to_default:
             tag: openstack.aodh