Code review comment for lp:~cjwatson/launchpad/snap-max-retries

LGTM. The store's timeout is tunable so we can make that lower easily but for now 18 minutes seems to be what we need. Setting this value to 30 should result in about 27:30 minutes of retries from Launchpad (up from the previous 17:30 which was uncomfortably close to the 18-minute store timeout).