Description of problem:
we frequently see error messages like these in evm.log:

[----] I, [2017-02-10T09:11:25.320747 #32248:3ed140]  INFO -- : MIQ(MiqGenericWorker::Runner#get_message_via_drb) Message id: [80000554707927], MiqWorker id: [80000009586613], Zone: [BDC-WK], Role: [], Server: [], Ident: [generic], Target id: [], Instance id: [], Task id: [], Command: [MiqTask.destroy], Timeout: [600], Priority: [100], State: [dequeue], Deliver On: [], Data: [], Args: [[80000001507926]], Dequeued in: [3.136616649] seconds
[----] I, [2017-02-10T09:11:25.322633 #32248:3ed140]  INFO -- : MIQ(MiqQueue#deliver) Message id: [80000554707927], Delivering...
[----] I, [2017-02-10T09:11:25.340553 #31874:3ed140]  INFO -- : MIQ(MiqGenericWorker::Runner#get_message_via_drb) Message id: [80000554707922], MiqWorker id: [80000009586609], Zone: [BDC-WK], Role: [automate], Server: [], Ident: [generic], Target id: [], Instance id: [], Task id: [], Command: [MiqAeEngine.deliver], Timeout: [3600], Priority: [20], State: [dequeue], Deliver On: [], Data: [], Args: [{:object_type=>"EmsEvent", :object_id=>80000107809433, :attrs=>{:event_id=>80000107809433, :event_stream_id=>80000107809433, :event_type=>"HealthStatusChangedEvent", "ExtManagementSystem::ems"=>80000000000010, :ems_id=>80000000000010}, :instance_name=>"Event", :user_id=>80000000000001, :miq_group_id=>80000000000001, :tenant_id=>80000000000001, :automate_message=>nil}], Dequeued in: [3.817298632] seconds
[----] I, [2017-02-10T09:11:25.341930 #31874:3ed140]  INFO -- : MIQ(MiqQueue#deliver) Message id: [80000554707922], Delivering...
[----] I, [2017-02-10T09:11:25.388369 #31874:3ed140]  INFO -- : MIQ(MiqAeEngine.deliver) Delivering {:event_id=>80000107809433, :event_stream_id=>80000107809433, :event_type=>"HealthStatusChangedEvent", "ExtManagementSystem::ems"=>80000000000010, :ems_id=>80000000000010} for object [EmsEvent.80000107809433] with state [] to Automate[----] I, [2017-02-10T09:11:25.437249 #31874:3ed140]  INFO -- : <AutomationEngine> Instantiating [/System/Process/Event?EventStream%3A%3Aevent_stream=80000107809433&ExtManagementSystem%3A%3Aems=80000000000010&MiqServer%3A%3Amiq_server=80000000000020&User%3A%3Auser=80000000000001&ems_id=80000000000010&event_id=80000107809433&event_stream_id=80000107809433&event_type=HealthStatusChangedEvent&object_name=Event&vmdb_object_type=event_stream]
[----] E, [2017-02-10T09:11:25.492564 #32248:3ed140] ERROR -- : MIQ(MiqQueue#deliver) Message id: [80000554707927], Error: [Couldn't find MiqTask with 'id'=80000001507926]
[----] E, [2017-02-10T09:11:25.493799 #32248:3ed140] ERROR -- : [ActiveRecord::RecordNotFound]: Couldn't find MiqTask with 'id'=80000001507926  Method:[rescue in deliver]
[----] E, [2017-02-10T09:11:25.494220 #32248:3ed140] ERROR -- : /opt/rh/cfme-gemset/gems/activerecord-5.0.0.1/lib/active_record/relation/finder_methods.rb:357:in `raise_record_not_found_exception!'
/opt/rh/cfme-gemset/gems/activerecord-5.0.0.1/lib/active_record/relation/finder_methods.rb:477:in `find_one'
/opt/rh/cfme-gemset/gems/activerecord-5.0.0.1/lib/active_record/relation/finder_methods.rb:456:in `find_with_ids'
/opt/rh/cfme-gemset/gems/activerecord-5.0.0.1/lib/active_record/relation/finder_methods.rb:66:in `find'
/opt/rh/cfme-gemset/gems/activerecord-5.0.0.1/lib/active_record/relation.rb:491:in `destroy'
/opt/rh/cfme-gemset/gems/activerecord-5.0.0.1/lib/active_record/relation.rb:489:in `block in destroy'
Version-Release number of selected component (if applicable):
CloudForms 4.2

How reproducible:


Steps to Reproduce:
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Actual results:


Expected results:


Additional info: