fix(command): add missing help message for '--keystore-factory'

[halibobo1205]

What does this PR do?
Add missing help message for '--keystore-factory', pre-PR #6446.
Why are these changes required?
java -jar FullNode.jar -h show --keystore-factory

 Name:
 FullNode - the java-tron command line interface

Usage: java -jar FullNode.jar [options] [seedNode <seedNode> ...]

VERSION: 
4.8.1-74118c1

TRON OPTIONS:
-v, --version                           Output code version
-h, --help                              Show help message
-c, --config                            Config file (default:config.conf)
--log-config                            Logback config file
--es                                    Start event subscribe server
--solidity                              Running a solidity node for java tron
--keystore-factory                      Running KeystoreFactory

DB OPTIONS:
-d, --output-directory                  Data directory for the databases (default:output-directory)

WITNESS OPTIONS:
-w, --witness                           Is witness node
-p, --private-key                       Witness private key

VIRTUAL MACHINE OPTIONS:
--debug                 Switch for TVM debug mode. In debug model, TVM will not check for timeout. (default: false)

This PR has been tested by:

• Unit Tests
• Manual Testing

Follow up

Extra details