In my devices I've two Loopback-IPs configured.
ip address 22.214.171.124 255.255.255.255
ip address 126.96.36.199 255.255.255.255
Is it possible to define in CW that the IP from loopback 0 is the Management-IP.
In the Discovery-Settings I only can say under "Preferred Management IP" -> "Use LoopBack Address"
But I want the Loopback0 as Management-IP not Loopback1
The discovery algorithm is set to choose the highest loopback address. So if you want to have loopback 0 as the management IP, you need to assign a higher IP to it. See this discovery DOC which has very detailed explanations.