Fix FELIX-4127

Release the configuration tracker instance when iPOJO stops.

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1493039 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/ConfigurationTracker.java b/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/ConfigurationTracker.java
index 80942ba..7e61fb1 100644
--- a/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/ConfigurationTracker.java
+++ b/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/ConfigurationTracker.java
@@ -67,6 +67,7 @@
 
     public static void shutdown() {
         m_singleton.dispose();
+        m_singleton = null;
     }
 
     public static ConfigurationTracker get() {