fix: delete will from persistence on disconnect

[bmeverett]

Problem

I was using aedes-persistence-redis and noticed that if clients connect with a will message then the keys weren't being deleted on a clean disconnect

Solution

The keys should always be removed from the persistence regardless if the the client disconnects cleanly or not. When the client disconnects, the will no longer should matter so we can delete it. If the client connects again with another will, then we can retain that one.

[coveralls]

Pull Request Test Coverage Report for Build 9412573480

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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Details

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.001%) to 99.743%

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Totals
Change from base Build 9295732195:	0.001%
Covered Lines:	824
Relevant Lines:	824

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💛 - Coveralls