pg_upgrade: Bump MESSAGE_WIDTH.

pg_upgrade: Bump MESSAGE_WIDTH.

Commit 7b378237aa added a status message to pg_upgrade that is 60
characters wide.  Since the MESSAGE_WIDTH macro is currently set to
60, there is no space between this new status message and the "ok"
or "failed" indicator appended when the step completes.  To fix
this problem, this commit increases the value of MESSAGE_WIDTH to
62.

Suggested-by: Bharath Rupireddy
Reviewed-by: Peter Eisentraut
Discussion: https://postgr.es/m/CALj2ACVVvk1cYLtWVxHv%3DZ1Ubq%3DUES9fhKbUU4c9k4W%2BfEDnbw%40mail.gmail.com
Backpatch-through: 16