[client-connect] drop rqlst on rset returned client side The DBAPI used to drop the RQL syntax tree on rset to save bandwidth. We could stop doing it for In-memory client connection. However keeping the syntax tree leads to multiple tests failures. So we keep dropping it as the DBAPI always did. related to #2503918

raise NotImplementedError("Cannot migrate such an old version. Use intermediate Cubiweb version (try 3.16.x)")