Unfortunately this isn't possible. The only way to edit the connection URL would be by editing the connection from the data source page.
There are few related ideas in the ideas forum currently, like this one: https://community.tableau.com/ideas/5673
If you think that would solve your problem, feel free to vote for that idea! We utilize the idea forum frequently when trying to prioritize what we build next. And if you have something else in mind and can't find it in the forum, please feel free to create your own idea request!