Remove double-dash parameters from mapArgs
Remove double-dash parameters from mapArgs

Should be merged after pull request #4281
("Add `-version` option to get just the version #4281"),
because is changed "--help" to "-help".

Checked that grep of 'mapArgs.count("--' returned only
three places that are fixed by pull request #4281.

(cherry picked from commit 71aaff393f06378150612fc618b6c3f84c1d2066)

reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin