[Pkg-postgresql-public] Bug#756008: pg_upgradecluster should use fast shutdown

[W. Martin Borgert]

Control: found -1 181+deb9u1

I just tried this after upgrading from Debian 8 to 9:

# pg_upgradecluster 9.4 main
Stopping old cluster...
Notice: extra pg_ctl/postgres options given, bypassing systemctl for  
stop operation
pg_ctl: server does not shut down
HINT: The "-m fast" option immediately disconnects sessions rather than
waiting for session-initiated disconnection.
Error: Could not stop old cluster
# pg_lsclusters
Ver Cluster Port Status Owner    Data directory               Log file
9.4 main    5432 online postgres /var/lib/postgresql/9.4/main  
/var/log/postgresql/postgresql-9.4-main.log
# pg_upgradecluster 9.4 main
psql: FATAL:  the database system is shutting down
psql: FATAL:  the database system is shutting down
Use of uninitialized value $out in pattern match (m//) at  
/usr/share/perl5/PgCommon.pm line 944.
psql: FATAL:  the database system is shutting down
Use of uninitialized value $out in pattern match (m//) at  
/usr/share/perl5/PgCommon.pm line 950.
Use of uninitialized value $ctype in scalar chomp at  
/usr/share/perl5/PgCommon.pm line 953.
Use of uninitialized value $collate in scalar chomp at  
/usr/share/perl5/PgCommon.pm line 954.
Error: could not get cluster locales
# pg_lsclusters
Ver Cluster Port Status Owner    Data directory               Log file
9.4 main    5432 online postgres /var/lib/postgresql/9.4/main  
/var/log/postgresql/postgresql-9.4-main.log