Update JettyCachingLdapLoginModule.java : manage Referral Control

JNDI sets Manage Referral Control to ignore per default. This value prevents dynamic group usage with rundeck. Adding an option to change Manage Referral control default value allow dynamic groups usage.

- ignore : ignore referrals (default value as actually)
- follow :  automatically follow any referrals for dynamic groups

- https://docs.oracle.com/javase/tutorial/jndi/newstuff/mdsaIT.html
- pwm-project/pwm#610

rundeckapp/src/main/groovy/com/dtolabs/rundeck/jetty/jaas/JettyCachingLdapLoginModule.java

@@ -92,6 +92,7 @@
  *    rolePrefix="rundeck"
  *    cacheDurationMillis="500"
  *    reportStatistics="true"
+ *    referralControl="follow"
  *    nestedGroups="false";
  *    };
  * </pre>
@@ -155,6 +156,11 @@ public class JettyCachingLdapLoginModule extends AbstractLoginModule {
      */
     protected String _contextFactory;
 
+    /**
+     * Context.REFERRAL
+     */
+    protected String _referralControl = "ignore";
+
     /**
      * root DN used to connect to
      */
@@ -1067,6 +1073,7 @@ public void initializeOptions(final Map options) {
             _port = Integer.parseInt((String) options.get("port"));
         }
         _providerUrl = (String) options.get("providerUrl");
+        _referralControl = (String) options.get("referralControl");
         _contextFactory = (String) options.get("contextFactory");
         _bindDn = (String) options.get("bindDn");
         String bindPassword = attemptBindPwdFromRdkConfig();
@@ -1232,6 +1239,8 @@ public Hashtable getEnvironment() {
             env.put(Context.SECURITY_CREDENTIALS, _bindPassword);
         }
 
+        env.put(Context.REFERRAL, referralControl);
+
         env.put("com.sun.jndi.ldap.read.timeout", Long.toString(_timeoutRead));
         env.put("com.sun.jndi.ldap.connect.timeout", Long.toString(_timeoutConnect));