Description of problem:

Undeploy works fine, the configuration is removed and the agent is stopped. However, the metadata for the host on shared storage is left behind. 

This does not cause any problems, but it leaves pollution on the output of hosted-engine --vm-status and may confuse the administrator if the host was really removed or something went wrong. It shows as a stale host, not stopped, not in local maintenance. Just left there, as if the host died. 

Perhaps it would be more user friendly if this was cleaned up during Undeploy.

--== Host 3 status ==--

conf_on_shared_storage             : True
Status up-to-date                  : False
Hostname                           : 10.64.24.171
Host ID                            : 3
Engine status                      : unknown stale-data
Score                              : 2601
stopped                            : False
Local maintenance                  : False
crc32                              : 7b82abf2
local_conf_timestamp               : 1158
Host timestamp                     : 1157
Extra metadata (valid at timestamp):
	metadata_parse_version=1
	metadata_feature_version=1
	timestamp=1157 (Wed Jan 17 10:20:55 2018)
	host-id=3
	score=2601
	vm_conf_refresh_time=1158 (Wed Jan 17 10:20:56 2018)
	conf_on_shared_storage=True
	maintenance=False
	state=GlobalMaintenance
	stopped=False



Version-Release number of selected component (if applicable):
rhevm-4.1.8.2-0.1.el7.noarch

How reproducible:
100%

Steps to Reproduce:
1. Undeploy host

Actual results:
Host metadata on SD left behind.

Expected results:
Host metadata cleaned up