fix: NotEqualTo trigger no longer matches non-existent properties#1625

nan-li merged 2 commits intomainOneSignal/OneSignal-iOS-SDK:mainfrom

fix/iam_not_equal_trigger_when_nonexistentOneSignal/OneSignal-iOS-SDK:fix/iam_not_equal_trigger_when_nonexistentCopy head branch name to clipboard