**Describe the bug**
```
5828589:2021.04.27 03:13:08.824665 [ 6101 ] {} <Trace> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94): Renaming temporary part tmp_merge_all_0_4_7_17 to all_0_4_7_17.
5828590:2021.04.27 03:13:08.824778 [ 3358 ] {} <Trace> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461): Renaming temporary part tmp_merge_all_0_4_7_17 to all_0_4_7_17.
5828591:2021.04.27 03:13:08.824823 [ 6101 ] {} <Warning> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94): Tried to add obsolete part all_0_4_7_17 covered by all_0_4_13_34 (state Committed)
5828623:2021.04.27 03:13:08.824951 [ 3358 ] {} <Warning> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461): Tried to add obsolete part all_0_4_7_17 covered by all_0_4_13_34 (state Committed)
5828624:2021.04.27 03:13:08.824995 [ 6101 ] {} <Warning> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94) (MergerMutator): Unexpected number of parts removed when adding all_0_4_7_17: 0 instead of 1
5828625:2021.04.27 03:13:08.825147 [ 3358 ] {} <Warning> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461) (MergerMutator): Unexpected number of parts removed when adding all_0_4_7_17: 0 instead of 1
5828643:2021.04.27 03:13:08.831273 [ 3358 ] {} <Trace> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461): Trying to immediately remove part all_0_4_7_17 (state Temporary)
5828644:2021.04.27 03:13:08.831658 [ 3358 ] {} <Fatal> : Logical error: 'Part all_0_4_7_17 doesn't exist'.
5828648:2021.04.27 03:13:08.832767 [ 6101 ] {} <Trace> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94): Trying to immediately remove part all_0_4_7_17 (state Temporary)
5828649:2021.04.27 03:13:08.833210 [ 6101 ] {} <Fatal> : Logical error: 'Part all_0_4_7_17 doesn't exist'.

```

https://clickhouse-test-reports.s3.yandex.net/0/9bb4d8769f1064ada4cce6b26d8ff61c11356965/stress_test_(debug).html#fail1
return res;
    time_t now = time(nullptr);
    std::vector<DataPartIteratorByStateAndInfo> parts_to_delete;
    {
        auto parts_lock = lockParts();
        auto outdated_parts_range = getDataPartsStateRange(DataPartState::Outdated);
        for (auto it = outdated_parts_range.begin(); it != outdated_parts_range.end(); ++it)
        {
            const DataPartPtr & part = *it;
            auto part_remove_time = part->remove_time.load(std::memory_order_relaxed);
            if (part.unique() && 
                ((part_remove_time < now &&
                now - part_remove_time > getSettings()->old_parts_lifetime.totalSeconds()) || force
                || isInMemoryPart(part))) 
            {
                parts_to_delete.emplace_back(it);
            }
        }
        res.reserve(parts_to_delete.size());
        for (const auto & it_to_delete : parts_to_delete)
        {
            res.emplace_back(*it_to_delete);
            modifyPartState(it_to_delete, DataPartState::Deleting);
        }
    }
    if (!res.empty())
        LOG_TRACE(log, "Found {} old parts to remove.", res.size());
    return res;
}
void MergeTreeData::rollbackDeletingParts(const MergeTreeData::DataPartsVector & parts)