Description of problem:
pgbouncer systemctl start times out.


Version-Release number of selected component (if applicable):
1.13.0-2.el8

How reproducible:
always

Steps to Reproduce:
1. Install pgbouncer from EPEL and PostgreSQL 12 from CentOS 8 stream
2. Configure /etc/pgbouncer/pgbouncer.ini and /etc/pgbouncer/userlist.txt
3. Accordingly configure and start PostgreSQL 12 server
4. Run sudo systemctl start pgbouncer

Actual results:
systemctl start pgbouncer times out.

Expected results:
systemctl start pgbouncer succeeds in time.

Additional info:
$ sudo tail /var/log/pgbouncer/pgbouncer.log
2020-08-13 08:00:28.722 EDT [9233] LOG kernel file descriptor limit: 1024 (hard: 262144); max_client_conn: 33000, max expected fd use: 33212
2020-08-13 08:00:28.722 EDT [9233] LOG listening on 127.0.0.1:6432
2020-08-13 08:00:28.722 EDT [9233] LOG listening on unix:/tmp/.s.PGSQL.6432
2020-08-13 08:00:28.722 EDT [9233] LOG process up: PgBouncer 1.13.0, libevent 2.1.8-stable (epoll), adns: evdns2, tls: OpenSSL 1.1.1c FIPS  28 May 2019
2020-08-13 08:01:28.722 EDT [9233] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2020-08-13 08:02:28.723 EDT [9233] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2020-08-13 08:03:28.723 EDT [9233] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2020-08-13 08:04:28.723 EDT [9233] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2020-08-13 08:05:28.723 EDT [9233] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2020-08-13 08:05:28.823 EDT [9233] LOG got SIGTERM, fast exit

$ sudo strace -p 9233
strace: Process 9233 attached
epoll_wait(4, [], 32, 333)              = 0
stat("/etc/pgbouncer/userlist.txt", {st_mode=S_IFREG|0600, st_size=24, ...}) = 0
getpid()                                = 9233
write(3, "2020-08-13 08:05:28.723 EDT [923"..., 124) = 124
epoll_wait(4, 0x55d1e769a060, 32, 333)  = -1 EINTR (Interrupted system call)
epoll_wait(4, [{EPOLLIN, {u32=5, u64=5}}], 32, 234) = 1
read(5, "\17", 1024)                    = 1
read(5, 0x7f4131b284c0, 1024)           = -1 EAGAIN (Resource temporarily unavailable)
getpid()                                = 9233
write(3, "2020-08-13 08:05:28.823 EDT [923"..., 62) = 62
unlink("/var/run/pgbouncer/pgbouncer.pid") = 0
close(8)                                = 0
close(9)                                = 0
unlink("/tmp/.s.PGSQL.6432")            = 0
exit_group(1)                           = ?