Cfn-python-lint: Duplicate error for missing param

[adamchainz]

cfn-lint version: (cfn-lint --version) master

Description of issue.

When referencing a missing param in a !Sub, E1012 and E1019 both detect it. Probably only one should.

$ cat test.yml
Resources:
  Test:
    Type: AWS::SNS::Topic
    Properties:
      TopicName: !Sub ${MissingParam}
$ cfn-lint test.yml
E1012 Ref MissingParam not found as a resource or parameter
test.yml:5:7

E1019 Parameter MissingParam for Fn::Sub not found at Resources/Test/Properties/TopicName/Fn::Sub
test.yml:5:7

[cmmeyer]

Yeah, redundant. I can flag this as a bug and we'll dig into it.

[cmmeyer]

Merged PR #370 for this. Closing the issue.