Fix issue with cleaning shared ref-db when project deleted

During the code merge binding for ProjectDeletedListener was lost.

Change-Id: I61b96015243254c52b8e821abbdcb59fe2c75f0c
diff --git a/src/main/java/com/googlesource/gerrit/plugins/multisite/PluginModule.java b/src/main/java/com/googlesource/gerrit/plugins/multisite/PluginModule.java
index b27ae01..51db83f 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/multisite/PluginModule.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/multisite/PluginModule.java
@@ -15,13 +15,16 @@
 package com.googlesource.gerrit.plugins.multisite;
 
 import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.extensions.events.ProjectDeletedListener;
 import com.google.gerrit.extensions.registration.DynamicItem;
+import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.lifecycle.LifecycleModule;
 import com.google.inject.Inject;
 import com.google.inject.Scopes;
 import com.googlesource.gerrit.plugins.multisite.broker.BrokerApi;
 import com.googlesource.gerrit.plugins.multisite.kafka.KafkaBrokerApi;
 import com.googlesource.gerrit.plugins.multisite.kafka.KafkaBrokerModule;
+import com.googlesource.gerrit.plugins.multisite.validation.ProjectDeletedSharedDbCleanup;
 import com.googlesource.gerrit.plugins.multisite.validation.dfsrefdb.zookeeper.ZkValidationModule;
 
 public class PluginModule extends LifecycleModule {
@@ -47,6 +50,8 @@
       listener().to(PluginStartup.class);
       logger.atInfo().log("Shared ref-db engine: Zookeeper");
       install(zkValidationModule);
+      DynamicSet.bind(binder(), ProjectDeletedListener.class)
+          .to(ProjectDeletedSharedDbCleanup.class);
     }
 
     DynamicItem.bind(binder(), BrokerApi.class).to(KafkaBrokerApi.class).in(Scopes.SINGLETON);