check for = false explicitly instead of != true

[mwoolweaver]

What does this PR aim to accomplish?:

check for = false explicitly instead of != true.

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[yubiuser]

I'm not sure about this change. validSession is set by Authenticate() which get it from

https://github.com/mwoolweaver/PADD/blob/16423a6b6ada5e2a436d6b1ffdd79f4dd110a14d/padd.sh#L300C5-L300C17

If anything goes wrong, it might contain something unexpected or is empty. Therefore, I would keep this check as it was

[yubiuser]

Pinging @mwoolweaver