Use own Nullable instead of javax.annotation.Nullable.

Since d6ccccf96a238 Gerrit uses own Nullable annotation type and the jsr305
library was removed as it was not needed any more after that.

Change-Id: If79abec8d4acbcddbf2952c4cad44a04edfb75cb

src/main/java/com/googlesource/gerrit/plugins/replication/PushAll.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/PushAll.java b/src/main/java/com/googlesource/gerrit/plugins/replication/PushAll.java
index 301a861..25f4cde 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/PushAll.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/PushAll.java
@@ -14,6 +14,7 @@
 
 package com.googlesource.gerrit.plugins.replication;
 
+import com.google.gerrit.common.Nullable;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.git.WorkQueue;
 import com.google.gerrit.server.project.ProjectCache;
@@ -26,8 +27,6 @@
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 
-import javax.annotation.Nullable;
-
 class PushAll implements Runnable {
   private static final Logger log = LoggerFactory.getLogger(PushAll.class);
   private static final WrappedLogger wrappedLog = new WrappedLogger(log);