Re-enable test-submit for Gerrit server

The Gerrit command test-submit was accidentally removed
by Change-Id: I3342d304 when a non-replica server had
the Git/SSH protocol disabled.

Bug: Issue 13412
Change-Id: I267fea48a435541a7a50fc1476a5788deb9d4392
diff --git a/java/com/google/gerrit/sshd/commands/DefaultCommandModule.java b/java/com/google/gerrit/sshd/commands/DefaultCommandModule.java
index c7fe74e..cfd17f4 100644
--- a/java/com/google/gerrit/sshd/commands/DefaultCommandModule.java
+++ b/java/com/google/gerrit/sshd/commands/DefaultCommandModule.java
@@ -90,9 +90,12 @@
         command("git-receive-pack").to(Commands.key(git, "receive-pack"));
         command("gerrit-receive-pack").to(Commands.key(git, "receive-pack"));
         command(git, "receive-pack").to(Commands.key(gerrit, "receive-pack"));
-        command(gerrit, "test-submit").toProvider(new DispatchCommandProvider(testSubmit));
       }
     }
+
+    if (!slaveMode) {
+      command(gerrit, "test-submit").toProvider(new DispatchCommandProvider(testSubmit));
+    }
     command("suexec").to(SuExec.class);
     listener().to(ShowCaches.StartupListener.class);