Update docker-compose.yaml

mini server/docker-compose.yaml

-version: "3.3"
-
 services:
   miniwhoami_20412:
     image: docker.fslab.de/shussa2s/servmgmt-ss22:latest
     ports:
       - "20412:80"
     networks:
-      - mynetwork
-
+      my_ipv6_20412:
+        ipv6_address: 2001:638:408:200:fe50:cafe::2222/96
+    
   miniwhoami_20413:
     image: docker.fslab.de/shussa2s/servmgmt-ss22:latest
     ports:
       - "20413:80"
     networks:
-      - mynetwork
+      my_ipv6_20413:
+        ipv6_address: 2001:638:408:200:fe50:cafe::3333/96
 
 networks:
-  mynetwork:
+  my_ipv6_20412:
+    external: true
+  my_ipv6_20413:
+    external: true