Only update config if something's returned

src/main/java/alien/site/ComputingElement.java

@@ -119,7 +119,10 @@ public final class ComputingElement extends Thread {
 				logger.info("Building new SiteMap.");
 
 				try {
-					config = ConfigUtils.getConfigFromLdap();
+					final HashMap<String, Object> newConfig = ConfigUtils.getConfigFromLdap();
+					if (newConfig != null) {
+						config = newConfig;
+
 						site = (String) config.get("site_accountname");
 						getSiteMap();
 
@@ -129,6 +132,7 @@ public final class ComputingElement extends Thread {
 							logger.info("[" + field + ": " + entry + "]");
 						});
 					}
+				}
 				catch (Exception ex) {
 					logger.log(Level.WARNING, "Error syncing with LDAP: ", ex);
 				}