sonar change crit sect.

src/main/java/org/eclipse/openK/core/controller/ServicesConfigCache.java

diff --git a/src/main/java/org/eclipse/openK/core/controller/ServicesConfigCache.java b/src/main/java/org/eclipse/openK/core/controller/ServicesConfigCache.java
index 63ccfee..ae5f0d6 100644
--- a/src/main/java/org/eclipse/openK/core/controller/ServicesConfigCache.java
+++ b/src/main/java/org/eclipse/openK/core/controller/ServicesConfigCache.java
@@ -31,7 +31,7 @@
 public class ServicesConfigCache {
   private static final Logger logger = Logger.getLogger(ServicesConfigCache.class.getName());
     private static ServicesConfigCache instance = new ServicesConfigCache();
-  private static final String criticalSection="";
+  private static final Object lock = new Object();
 
   private ServiceDistributionCluster[] cache;
 
@@ -46,7 +46,7 @@
   public void readServerDistribution(String configFileName) throws HttpStatusException {
     try {
       ServiceDistributionCluster[] dcs = readServerDistributionFromText(new String(Files.readAllBytes(Paths.get(configFileName)), Charset.forName("UTF-8")));
-      synchronized( criticalSection ) {
+      synchronized( lock ) {
         cache = dcs;
       }
 
@@ -82,7 +82,7 @@
   }
 
   public ServiceDistributionCluster[] getCache() {
-    synchronized( criticalSection ) {
+    synchronized( lock ) {
       return cache;
     }
   }