ethstats: fix URL parser for '@' or ':' in node name/password (#21640)

Fixes the case (example below) where the value passed
to --ethstats flag would be parsed wrongly because the
node name and/or password value contained the special
characters '@' or ':'

    --ethstats "ETC Labs Metrics @meowsbits":mypass@ws://mordor.dash.fault.dev:3000