Remove unused GitRepositoryManager in replication.Destination

Change-Id: I6d590cefcbb107d76a7a3d6aaa2ba732f2ded63f

github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/replication/Destination.java

diff --git a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/replication/Destination.java b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/replication/Destination.java
index 0cdfe46..6519c16 100644
--- a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/replication/Destination.java
+++ b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/replication/Destination.java
@@ -43,7 +43,6 @@
 public class Destination {
   private final RemoteConfig remote;
   private final ProjectControl.Factory projectControlFactory;
-  private final GitRepositoryManager gitManager;
   private final String remoteNameStyle;
   private final CurrentUser remoteUser;
 
@@ -54,7 +53,6 @@
       final GitRepositoryManager gitRepositoryManager,
       final GroupBackend groupBackend) {
     remote = rc;
-    gitManager = gitRepositoryManager;
 
     remoteNameStyle =
         Objects.firstNonNull(