[FAB-10288] Fix nits in systemchaincode.rst
[FAB-10288] Fix nits in systemchaincode.rst

Small fixes.

Change-Id: Ia9a324500f96118578199d5ced2d01bd0393cbfa
Signed-off-by: joe-alewine <fe2d55ddcdde6f951d073228e1f2dc081e79a271@ibm.com>

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