[FAB-9643] Remove unreachable nil check
[FAB-9643] Remove unreachable nil check

This change set removes a nil check that is unreachable in the code.
The function retrieveCollectionConfigPackage can never return (nil, nil),
yet the caller function retrieveSimpleCollection checks for that condition.

Change-Id: I4731b5a219626aae081a39097666b10e2a06ae0f
Signed-off-by: yacovm <632344b5da9bd743456189af4db4b56472defb8c@il.ibm.com>

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