Daemon: Don't install online reindexer in slave mode

Installing the online indexer in slave mode causes the daemon
startup to fail with:

  No implementation for com.google.gerrit.server.index.VersionManager
  was bound

when the online indexer starts.

Bug: Issue 10452
Change-Id: I0bfe06bd6e0095f94d4433e0ba95f12134da1062
diff --git a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java
index 4f30e43..eb244db 100644
--- a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java
+++ b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java
@@ -413,7 +413,8 @@
     modules.add(new AuditModule());
     modules.add(new SignedTokenEmailTokenVerifier.Module());
     modules.add(new PluginModule());
-    if (VersionManager.getOnlineUpgrade(config)
+    if (!slave
+        && VersionManager.getOnlineUpgrade(config)
         // Schema upgrade is handled by OnlineNoteDbMigrator in this case.
         && !migrateToNoteDb()) {
       modules.add(new OnlineUpgrader.Module());