Remove unused imports

Change-Id: Ia836454597df488bab8d5e410d7b0ac0ed35550f
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java
index 749bae3..594b4e4 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java
@@ -111,7 +111,6 @@
 import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Ref;
-import org.eclipse.jgit.lib.RefDatabase;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.notes.NoteMap;
 import org.eclipse.jgit.revwalk.FooterKey;
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/index/ChangeBatchIndexer.java b/gerrit-server/src/main/java/com/google/gerrit/server/index/ChangeBatchIndexer.java
index 01b684f..c1ee9b0 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/index/ChangeBatchIndexer.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/index/ChangeBatchIndexer.java
@@ -46,7 +46,6 @@
 import org.eclipse.jgit.lib.ObjectInserter;
 import org.eclipse.jgit.lib.ProgressMonitor;
 import org.eclipse.jgit.lib.Ref;
-import org.eclipse.jgit.lib.RefDatabase;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevObject;