fix create envelope seek info for bft blocksprovider #240

Job	Run time
Basic Checks	1m 9s
Integration Tests (raft)	12m 43s
Integration Tests (pvtdata)	14m 56s
Integration Tests (ledger)	15m 8s
Integration Tests (lifecycle)	10m 50s
Integration Tests (pvtdatapurge)	4m 9s
Integration Tests (gateway idemix pkcs11 configtx configtxlator)	7m 5s
Integration Tests (sbe nwo msp)	8m 59s
Integration Tests (e2e smartbft)	27m 14s
Integration Tests (discovery gossip devmode pluggable)	10m 25s
Unit Tests	6m 41s
	1h 59m 19s

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