UpdateFingerprintRelationsUpgradeWizard is broken

[Mabahe]

Two issues:

1. visitor WHERE is missing
   https://github.com/in2code-de/lux/blob/develop/Classes/Update/UpdateFingerprintRelationsUpgradeWizard.php#L50

2. In a second run (first was not finished) also visitors get selected where fingerprints colums already contains the count, which scrambles the relations.
   https://github.com/in2code-de/lux/blob/develop/Classes/Update/UpdateFingerprintRelationsUpgradeWizard.php#L62

PR follows

[einpraegsam]

Thx for digging into this issue