fix: let postgresql handle its pidfile

monit.conf

@@ -1,4 +1,4 @@
-check process postgresql with pidfile /run/postgresql.pid
+check process postgresql with pidfile /run/postgresql/pid
   start program = "/usr/local/bin/postgresqld start"
   stop program = "/usr/local/bin/postgresqld stop"
   if failed port 5432 protocol pgsql for 3 times within 5 cycles then restart

postgresql.conf

@@ -1,5 +1,5 @@
 listen_addresses = '*'
-external_pid_file = '/run/postgresql.pid'
+external_pid_file = '/run/postgresql/pid'
 log_destination = 'syslog'
 log_checkpoints = on
 log_connections = on

postgresqld.sh

@@ -9,8 +9,6 @@ case $1 in
   reload)
     su ${user} -c "pg_ctl reload -D ${PGDATA}" ;;
   *)
-    pid=/run/postgresql.pid
-
     install -dm 2750 -o ${user} -g ${user} /run/postgresql
     chown -R ${user}:${user} ${PGBASE}
 
@@ -20,7 +18,6 @@ case $1 in
       echo "include_dir = '/etc/postgres.d'" >> ${PGDATA}/postgresql.conf
     fi
 
-    rm -f ${pid}
     daemonize -u ${user} -c ${PGDATA} /usr/bin/postgres
     ;;
 esac