[PATCH] test: enable parallel mode for wal_off tests

[Vladimir Davydov]

On Sat, Sep 22, 2018 at 04:44:17AM +0300, Alexander Turenko wrote:
> Vova, can you please confirm that memtx_memory option should be
> increased in the test? I mean confirm that it is the test problem and is
> not a problem of tarantool itself.

Looks like this is a bug in Tarantool after all:

  https://github.com/tarantool/tarantool/issues/3633#issuecomment-424425046