Do not hardcode groupId in VirtualCorpusServiceTest.testEditPublishVC

This seems to break the test on some systems, see:

https://github.com/KorAP/Kustvakt/runs/1988876680#step:10:2607

Change-Id: Iee1fef5d0ff39b1f43e884dbe5b9724c06829e24
diff --git a/full/src/test/java/de/ids_mannheim/korap/service/VirtualCorpusServiceTest.java b/full/src/test/java/de/ids_mannheim/korap/service/VirtualCorpusServiceTest.java
index 1185bae..deb03dc 100644
--- a/full/src/test/java/de/ids_mannheim/korap/service/VirtualCorpusServiceTest.java
+++ b/full/src/test/java/de/ids_mannheim/korap/service/VirtualCorpusServiceTest.java
@@ -141,8 +141,8 @@
 
         KustvaktException e = assertThrows(KustvaktException.class,
                 () -> groupService.retrieveUserGroupById(groupId));
-        
-        assertEquals("Group with id 5 is not found", e.getMessage());
+
+        assertEquals("Group with id " + groupId  + " is not found", e.getMessage());
     }
 
 }