Yeah, I guess it's a little bad to help crack a password but it also doesn't seem like a huge deal. Part of the stuff that Assange leaked included footage of American helicopters murdering people - which seems like a much bigger deal. If I crack your password and read your email and discover you're a serial killer, then yes, I've done wrong and should be punished for the minor crime I've committed, but you should be punished for the serial killing too.
In my view Assange should be sentenced to a hundred hours of community service immediately after the people responsible for planning and executing the vastly more consequential crimes Assange revealed are sentenced to lengthy prison sentences.