narval #1673783 don't cleanup Plan subclasses [resolved]

eg TestExecution. This is because it commit without further call to set_pool, so we don't have any pool set when trying to run subclasses queries

priorityimportant
typebug
done in3.0.4
load0.100
load left0.000
closed by#63ef26d41c25 closes #1673783: don't cleanup Plan subclasses due to missing call to set_pool after commit