Fix FloggerStringConcatenation bug pattern flagged by error prone

Change-Id: I9af802c6262e59b714ea5dd28066ff3b9111e382
Details: https://errorprone.info/bugpattern/FloggerStringConcatenation
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/ChainedScheduler.java b/src/main/java/com/googlesource/gerrit/plugins/replication/ChainedScheduler.java
index 89b97e9..5aef69e 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/ChainedScheduler.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/ChainedScheduler.java
@@ -109,7 +109,7 @@
       try {
         runner.run(item);
       } catch (RuntimeException e) { // catch to prevent chain from breaking
-        logger.atSevere().withCause(e).log("Error while running: " + item);
+        logger.atSevere().withCause(e).log("Error while running: %s", item);
       }
       if (!scheduledNext) {
         runner.onDone();