Improve pg_upgrade wording for pg_ctl start failure;  could be connection failure.
Improve pg_upgrade wording for pg_ctl start failure;  could be
connection failure.

Backpatch to 9.2.

Per report from Evan D. Hoffman

arcivanov/postgres-xl,kmjungersen/PostgresXL,postmind-net/postgres-xl,snaga/postgres-xl,postmind-net/postgres-xl,postmind-net/postgres-xl,kmjungersen/PostgresXL,arcivanov/postgres-xl,arcivanov/postgres-xl,kmjungersen/PostgresXL,snaga/postgres-xl,snaga/postgres-xl,kmjungersen/PostgresXL,postmind-net/postgres-xl,arcivanov/postgres-xl,arcivanov/postgres-xl,snaga/postgres-xl,arcivanov/postgres-xl,snaga/postgres-xl,postmind-net/postgres-xl,kmjungersen/PostgresXL