Fix a few more app startup/shutdown problems

Change-Id: Ideb48a1e845ae345306fa10ec55499c471566ce7
diff --git a/protocols/isis/ctl/src/main/java/org/onosproject/isis/controller/impl/Controller.java b/protocols/isis/ctl/src/main/java/org/onosproject/isis/controller/impl/Controller.java
index 8e1006e..381109e 100644
--- a/protocols/isis/ctl/src/main/java/org/onosproject/isis/controller/impl/Controller.java
+++ b/protocols/isis/ctl/src/main/java/org/onosproject/isis/controller/impl/Controller.java
@@ -77,7 +77,9 @@
     public void isisDeactivate() {
         disconnectExecutor();
         processes = null;
-        peerExecFactory.shutdown();
+        if (peerExecFactory != null) {
+            peerExecFactory.shutdown();
+        }
     }
 
     /**