NIFI-9229 Flow upgrade not possible if a Output Port changes to a funnel

[timeabarna]

https://issues.apache.org/jira/browse/NIFI-9229

Description of PR

Fixing bug NIFI-9229

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[adenes]

Thanks @timeabarna for the fix. Overall the change looks good to me and works as expected. I only had a few minor comments.

[timeabarna]

Thanks @adenes for your help, I've modified the code based on your recommendations.

[adenes]

Thanks @timeabarna for the follow-up commit, the fix looks good to me. Merging to main.