Linkifier: Fix incorrect string formatting placeholders in log calls

Change-Id: Ic007a197374c7f4834ae4c679910a6fe474201e4
diff --git a/java/com/google/gitiles/Linkifier.java b/java/com/google/gitiles/Linkifier.java
index c997b8a..bf689ef 100644
--- a/java/com/google/gitiles/Linkifier.java
+++ b/java/com/google/gitiles/Linkifier.java
@@ -72,7 +72,7 @@
                 + "Did you copy it from a gerrit config?");
       }
       if (Strings.isNullOrEmpty(match)) {
-        log.warn("invalid commentlink.%s.match", subsection);
+        log.warn("invalid commentlink.{}.match", subsection);
         continue;
       }
       Pattern pattern;
@@ -88,7 +88,7 @@
         continue;
       }
       if (Strings.isNullOrEmpty(link)) {
-        log.warn("invalid commentlink.%s.link", subsection);
+        log.warn("invalid commentlink.{}.link", subsection);
         continue;
       }
       list.add(new CommentLinkInfo(pattern, link));