GUACAMOLE-220: Manually recurse through the group membership graph if the database engine does not support recursive queries.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-sqlserver/src/main/java/org/apache/guacamole/auth/sqlserver/SQLServerEnvironment.java

@@ -250,5 +250,10 @@ public class SQLServerEnvironment extends JDBCEnvironment {
             SQLSERVER_DEFAULT_DRIVER
         );
     }
-    
+
+    @Override
+    public boolean isRecursiveQuerySupported() {
+        return true; // All versions of SQL Server support recursive queries through CTEs
+    }
+
 }