[FAB-8383] remove mention of specific kafka ver.
[FAB-8383] remove mention of specific kafka ver.

Removed paragraph that mentioned the version of
kafka incuded in our sample images. This info
can be found in the upgrade doc.

Change-Id: Ib73520911286174ed75107a02cee1ce77ef0d9f1
Signed-off-by: Luis Sanchez <d8bd67fe98ca98b3efc5c9f9c3327e96bf910849@us.ibm.com>

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