[patches] [PATCH] sql: remove unnecessary SCopy opcodes

[n.pettik]

Hello. Please, don't send patch until you are sure that all tests are
passed, at least locally. I have checkouted to your branch and no one
test is passed (due to assertions).

Also, you don't have to put brief overview to patch, since it consists
from single commit. If you are willing to explaing smth, better do it
in commit message.