Description of problem:
after following the steps of https://cloudformsblog.redhat.com/2018/03/27/cloudforms-in-aws-part-2/, attempting to run smartstate analysis raises a "no agent is setup to process requests : undefined method `gateway_id` for nil:NilClass

Version-Release number of selected component (if applicable):
5.9.4

How reproducible:
customer environment

Steps to Reproduce:
1. follow the configuration steps of https://cloudformsblog.redhat.com/2018/03/27/cloudforms-in-aws-part-2/
2. start a smartstate
3.

Actual results:
[----] I, [2019-02-13T12:34:24.738484 #22036:fe310c]  INFO -- : MIQ(ManageIQ::Providers::Amazon::AgentCoordinator#deploy_agent) Deploying agent ...
[----] I, [2019-02-13T12:34:24.740862 #22036:fe310c]  INFO -- : MIQ(ManageIQ::Providers::Amazon::AgentCoordinator#find_or_create_keypair) KeyPair smartstate-ebe6530c-8133-43d1-a006-14d3e0d62bd2 will be created!
[----] D, [2019-02-13T12:34:25.256997 #22036:fe310c] DEBUG -- : MIQ(ManageIQ::Providers::Amazon::AgentCoordinator#enabled_internet_gateways?) Found a gateway [igw-e097e385] on VPC [vpc-8a112eef]
[----] D, [2019-02-13T12:34:25.306880 #22036:fe310c] DEBUG -- : MIQ(ManageIQ::Providers::Amazon::AgentCoordinator#enabled_internet_gateways?) Found route tables [#<Aws::EC2::RouteTable id="rtb-6222c306">] on the gateway [igw-e097e385]
[----] D, [2019-02-13T12:34:25.467077 #22036:fe310c] DEBUG -- : MIQ(ManageIQ::Providers::Amazon::AgentCoordinator#enabled_internet_gateways?) Found a gateway [igw-0805e9a617ab8d148] on VPC [vpc-011e68c42633d689a]
[----] E, [2019-02-13T12:34:25.522052 #22036:fe310c] ERROR -- : MIQ(ManageIQ::Providers::Amazon::AgentCoordinator#startup_agent) No agent is set up to process requests: undefined method `gateway_id' for nil:NilClass

Expected results:
the smartstate analysis completes

Additional info:
looking into having the customer reproduce in 5.9.7