Merge #10085: Docs: remove 'noconnect' option

Summary:
Backport of Core PR10085
https://github.com/bitcoin/bitcoin/pull/10085/files

Test Plan:

make
bitcoind --help | grep -A2 "\-dnsseed"
bitcoind --help | grep -A2 "\-listen"
# Verify noconnect is no longer present in the help messages

Reviewers: #bitcoin_abc, deadalnix, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D3841