Guys, please, don’t ignore this patch. It is vital for 2.1.1 release.

> On 20 Mar 2019, at 18:38, Kirill Shcherbatov <kshcherbatov@tarantool.org> wrote:
>>>> Tarantool could not start from the snapshot created by version
>>>> 2.1.0 because the new version 2.1.1 does not support the
>>>> index.opts.sql index opt and stops the execution.
>>>> Introduced a special state OPT_DEF_LEGACY macro to ignore legacy
>>>> options and introduced migration code in upgrade.lua.
>>> 
>>> As for me, it looks satisfying, but I strongly recommend you to ask
>>> other members of server team for comments on this approach.
>>> Will there be other “legacy” options, or in the nearest future this is
>>> going to be the only one? Moreover, opts_parse_key already features
>>> “skip_unknown_options” param - could we skip “sql” option using it
>>> (ofc considering some workaround)?
>>> 
>>> Again, since it is not directly related to the main patch-set, let’s
>>> consider it as independent. 
>> 
>> LGTM.
> 
> I've rebased this separate patch on the branch 
> kshch/migration-fixup
> you may cherry-pick it if it is really reasonable.