Repeatable read violation with reverse iterator in memtx

[CuriousGeorgiy]

Steps to reproduce

os.execute('rm -rf *.snap *.xlog *.vylog 512')

local json = require('json')
local log = require('log')
local txn_proxy = require('txn_proxy')

box.cfg{memtx_use_mvcc_engine = true}

box.schema.space.create('s')
box.space.s:create_index('pk')

box.internal.memtx_tx_gc(1)

local tx1 = txn_proxy:new()
local tx2 = txn_proxy:new()
local tx3 = txn_proxy:new()

tx1('box.begin()')
tx2('box.begin()')
tx3('box.begin()')


tx1('box.space.s:insert{2}')
tx1('box.rollback()')

tx2('box.space.s:insert{0}')
log.info('%s', json.encode(tx3('box.space.s:select({1}, {iterator = "LE", fullscan = true})')))


box.space.s:insert{1}
log.info('%s', json.encode(tx3('box.space.s:select({1}, {iterator = "LE", fullscan = true})')))

os.exit()

Actual behavior

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[[[1]]]
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Expected behavior

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[[]]
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