Description of problem:
Cloudforms doesn't capture event from Openstack Ceilometer

Version-Release number of selected component (if applicable):
CFME 5.10.5.1 and RHOSP 10
 
How reproducible:
Always

Steps to Reproduce:
1. Deploy Openstack with ceilometer and configure ceilometer to store events
2. Deploy CloudForms
3. Add Openstack as provider 
4. Create image in Openstack
5. Observe logs in CloudForms for event capture.

Actual results:
Cloudforms doesn't capture event from Openstack Ceilometer

Expected results:
Cloudforms should capture the event from Openstack Ceilometer, which will then perform the targeted refresh for the provider.

Additional info:

The events are observed in Openstack, 
~~~
ceilometer event-list

| 612e98d9-23fb-455a-8ab1-9358e074b8b1 | image.create                        | 2019-06-20T07:02:24.539000 | +-------------+--------+--------------------------------------+                  |
|                                      |                                     |                            | |     name    |  type  |                value                 |                  |
|                                      |                                     |                            | +-------------+--------+--------------------------------------+                  |
|                                      |                                     |                            | |  created_at | string |         2019-06-20T07:02:24Z         |                  |
|                                      |                                     |                            | |     name    | string |             cirros-test5             |                  |
|                                      |                                     |                            | |  project_id | string |   69dba7b4214b4601af28a3df7fb3f9be   |                  |
|                                      |                                     |                            | | resource_id | string | 161850db-8a06-4212-9567-9aa2c80d49b1 |                  |
|                                      |                                     |                            | |   service   | string |           image.localhost            |                  |
|                                      |                                     |                            | |    status   | string |                queued                |                  |
|                                      |                                     |                            | |   user_id   | string |   69dba7b4214b4601af28a3df7fb3f9be   |                  |
|                                      |                                     |                            | +-------------+--------+--------------------------------------+                  |
~~~


However, in the evm.log, we see below logs show querying openStack for events without any timestamp:
~~~
[----] I, [2019-06-20T11:33:55.086470 #12442:df2834]  INFO -- : Querying OpenStack for events newer than ...
[----] I, [2019-06-20T11:33:59.494563 #12479:e03b48]  INFO -- : Querying OpenStack for events newer than ...
[----] I, [2019-06-20T11:34:00.037935 #12507:de1fd4]  INFO -- : Querying OpenStack for events newer than ...
~~~

In short, no events are being captured from openstack and targeted refresh does not happen.