Add a missing null check if security is enabled.

git-svn-id: https://svn.apache.org/repos/asf/incubator/felix/trunk@501399 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/framework/src/main/java/org/apache/felix/framework/Felix.java b/framework/src/main/java/org/apache/felix/framework/Felix.java
index f6f7f53..c64a9f9 100644
--- a/framework/src/main/java/org/apache/felix/framework/Felix.java
+++ b/framework/src/main/java/org/apache/felix/framework/Felix.java
@@ -2332,7 +2332,7 @@
 
         Object sm = System.getSecurityManager();
 
-        if (sm == null)
+        if ((sm == null) || (refs == null))
         {
             return refs;
         }