ServiceUserClassifierImpl: Reduce log about cyclic group to fine level

Having cyclic groups is not a problem for Gerrit, and hence it's okay if
cyclic groups exist. We do not need a warning about this. Reduce the log
level to FINE to reduce noise in our logs.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I92a83faac1171a54ed8985f9bd380f4c7c14f75a
diff --git a/java/com/google/gerrit/server/account/ServiceUserClassifierImpl.java b/java/com/google/gerrit/server/account/ServiceUserClassifierImpl.java
index 27ac9f4..db030f9 100644
--- a/java/com/google/gerrit/server/account/ServiceUserClassifierImpl.java
+++ b/java/com/google/gerrit/server/account/ServiceUserClassifierImpl.java
@@ -76,7 +76,7 @@
               .get(toTraverse.remove(0))
               .orElseThrow(() -> new IllegalStateException("invalid subgroup"));
       if (seen.contains(currentGroup.getGroupUUID())) {
-        logger.atWarning().log(
+        logger.atFine().log(
             "Skipping %s because it's a cyclic subgroup", currentGroup.getGroupUUID());
         continue;
       }