[FAB-11961] properly release resource
[FAB-11961] properly release resource

This CR fixes a minor bug - an iterator need to be properly released.

Change-Id: Ic05429f4978067250fa30e1d5c304e744160d37e
Signed-off-by: ping40 <3fdcdb40e75d7c7b82676a72401288e08659651a@gmail.com>

xixuejia/fabric,manish-sethi/fabric,manish-sethi/fabric-sidedb,binhn/fabric,xixuejia/fabric,manish-sethi/fabric-sidedb,stemlending/fabric,muralisrini/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,stemlending/fabric,manish-sethi/fabric-sidedb,jimthematrix/fabric,binhn/fabric,hyperledger/fabric,manish-sethi/fabric-sidedb,xixuejia/fabric,binhn/fabric,jimthematrix/fabric,muralisrini/fabric,hyperledger/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric,stemlending/fabric,stemlending/fabric,muralisrini/fabric