Fix issue 'No address associated with hostname'

[trentmc]

For #89, for the error reported in this comment: #89 (comment)

I was able to replicate it locally.

Notes:

• originally the service had url aquarius.rinkeby.v3.dev-ocean.com (and similar for provider)
• then we created the service aquarius.rinkeby.oceanprotocol.com, quite a while ago now. That's the ones we've been maintaining. The READMEs etc were not updated at the time. The old services at dev-ocean were / are still running.
• ocean.py READMEs point to *.dev-ocean.com not *.oceanprotocol.com #93 was to update the READMEs etc. Done. Except the wrong new url was provided: it had the v3 in it, and it shouldn't have.
• This PR fixes that problem.