title: Cloudformation won't deploy changes when default param is changed
body: <p>I have this template:</p>
  
  <pre><code>Parameters:
    ALBPort:
      Type: Number
      Description: The loab balancer port (how the app is accessed externally)
      Default: 8000 #changing this
    ...
  
  Resources:
    ALBListener:
      Type: AWS::ElasticLoadBalancingV2::Listener
      DependsOn: MyALB
      Properties:
        DefaultActions:
        - Type: forward
          TargetGroupArn: !Ref TargetGroup
        LoadBalancerArn: !Ref MyALB
        Port: !Ref ALBPort #changing this
        Protocol: HTTP
  </code></pre>
  
  <p>I change the default value in the template but when i redeploy:</p>
  
  <pre><code>No changes to deploy. Stack mystack is up to date
  </code></pre>
  
  <p>If I change it statically like <code>Port: 8001</code> CF sees the change</p>