Update supautils.conf.j2 | added deadlock_timeout

[TheOtherBrian1]

What kind of change does this PR introduce?

supautils update

What is the current behavior?

deadlock_timeout is not configurable

What is the new behavior?

Allow users to configure deadlock_timeout

Additional context

I personally haven't come across a user with a significant deadlock problem, but Postgres.ai wrote an article outlining how changing the setting at the session level can help detect certain migration issues