Log invalid gc schedule configuration

Change-Id: Ia40b163e156891f8fe351928e4c1d6073a6c34b7
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/GarbageCollectionRunner.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/GarbageCollectionRunner.java
index 68d25d9..e01924e 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/GarbageCollectionRunner.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/GarbageCollectionRunner.java
@@ -54,7 +54,8 @@
       if (delay == MISSING_CONFIG && interval == MISSING_CONFIG) {
         gcLog.info("Ignoring missing gc schedule configuration");
       } else if (delay < 0 || interval <= 0) {
-        gcLog.warn("Ignoring invalid gc schedule configuration");
+        gcLog.warn(String.format(
+            "Ignoring invalid gc schedule configuration: %s", scheduleConfig));
       } else {
         queue.getDefaultQueue().scheduleAtFixedRate(gcRunner, delay,
             interval, TimeUnit.MILLISECONDS);