Replace use of deprecated Repository#getReflogReader

Change-Id: I5e86a80d566b5177e1940da7a930ed366ac8f1bd

src/main/java/com/googlesource/gerrit/plugins/gitiles/FilteredRepository.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/gitiles/FilteredRepository.java b/src/main/java/com/googlesource/gerrit/plugins/gitiles/FilteredRepository.java
index b5843ab..f1b8b36 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/gitiles/FilteredRepository.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/gitiles/FilteredRepository.java
@@ -171,7 +171,7 @@
   @Nullable
   @Override
   public ReflogReader getReflogReader(String refName) throws IOException {
-    return exactRef(refName) != null ? delegate.getReflogReader(refName) : null;
+    return exactRef(refName) != null ? delegate.getRefDatabase().getReflogReader(refName) : null;
   }
 
   @Override
@@ -247,7 +247,7 @@
     @Override
     @NonNull
     public ReflogReader getReflogReader(@NonNull Ref ref) throws IOException {
-      return git.getReflogReader(ref);
+      return git.getRefDatabase().getReflogReader(ref);
     }
 
     @Override