HPCC-11718 MyAccount, passwordDaysRemaining can contain NULL

Fixes HPCC-11718

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #6092 from GordonSmith/HPCC-11718

HPCC-11718 MyAccount, passwordDaysRemaining can contain NULL

Reviewed-By: Miguel Vazquez <miguel.vazquez@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>