* Remove DryRun parameter in ec2_vpc_igw_facts check_mode
Using DryRun in check mode causes errors, and is not required
(as nothing changes when calling describe_internet_gateways)
Prevents the following error:
```
{"changed": false,
"failed": true,
"msg": "An error occurred (DryRunOperation) when calling
the DescribeInternetGateways operation: Request
would have succeeded, but DryRun flag is set."}
```
* ec2_vpc_igw_facts pep8 tidy up
e61be9ea78