GUACAMOLE-696: In JDBC module, merge effective groups.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/user/ModeledAuthenticatedUser.java

@@ -20,6 +20,7 @@
 package org.apache.guacamole.auth.jdbc.user;
 
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import org.apache.guacamole.net.auth.AuthenticatedUser;
@@ -168,5 +169,12 @@ public class ModeledAuthenticatedUser extends RemoteAuthenticatedUser {
     public void setIdentifier(String identifier) {
         user.setIdentifier(identifier);
     }
+    
+    @Override
+    public Set<String> getEffectiveUserGroups() {
+        Set<String> allGroups = new HashSet<>(user.getEffectiveUserGroups());
+        allGroups.addAll(super.getEffectiveUserGroups());
+        return Collections.unmodifiableSet(allGroups);
+    }
 
 }