Link directly to the deployment log when a deployment has failed

[toph-allen]

• When a (Python?) deployment fails (from rsconnect-python?), we don't surface the logs, or a link to the logs even, so it's hard to debug.
• It returns the content URL regardless, so when you go there, you just get a blank page or other error display.

When rsconnect-python was implemented, you couldn't link directly to logs in the Connect dashboard. You can now, so when a deployment fails, we should construct the URL to the log for the current deployment task and print it, rather than printing the link to the content URL.