GUACAMOLE-38: Clean up minor code issues.

extensions/guacamole-auth-quickconnect/src/main/java/org/apache/guacamole/auth/quickconnect/QuickConnectDirectory.java

@@ -50,7 +50,7 @@ public class QuickConnectDirectory extends SimpleDirectory<Connection> {
     /**
      * The internal counter for connection IDs.
      */
-    private AtomicInteger connectionId;
+    private final AtomicInteger connectionId;
 
     /**
      * Creates a new QuickConnectDirectory with the default

extensions/guacamole-auth-quickconnect/src/main/java/org/apache/guacamole/auth/quickconnect/QuickConnectUserContext.java

@@ -25,9 +25,7 @@ import org.apache.guacamole.GuacamoleException;
 import org.apache.guacamole.net.auth.AbstractUserContext;
 import org.apache.guacamole.net.auth.AuthenticationProvider;
 import org.apache.guacamole.net.auth.ConnectionGroup;
-import org.apache.guacamole.net.auth.Directory;
 import org.apache.guacamole.net.auth.User;
-import org.apache.guacamole.net.auth.simple.SimpleDirectory;
 import org.apache.guacamole.net.auth.simple.SimpleUser;
 
 /**

extensions/guacamole-auth-quickconnect/src/main/java/org/apache/guacamole/auth/quickconnect/QuickConnectionGroup.java

@@ -39,7 +39,7 @@ public class QuickConnectionGroup extends AbstractConnectionGroup {
     /**
      * A set that will store the Connection identifiers for this group.
      */
-    private Set<String> connectionIdentifiers =
+    private final Set<String> connectionIdentifiers =
             new HashSet<String>(Collections.<String>emptyList());
 
     /**

extensions/guacamole-auth-quickconnect/src/main/java/org/apache/guacamole/auth/quickconnect/rest/QuickConnectREST.java

@@ -38,7 +38,7 @@ public class QuickConnectREST {
     /**
      * The connection directory for this REST endpoint.
      */
-    private QuickConnectDirectory directory;
+    private final QuickConnectDirectory directory;
 
     /**
      * Construct a new QuickConnectREST class, taking in a