BUG #17032: wrong password cause double connect and double error

The following bug has been logged on the website:

Bug reference:      17032
Logged by:          RekGRpth
Email address:      rekgrpth@gmail.com
PostgreSQL version: 13.3
Operating system:   docker alpine
Description:

1) create user test with password test and database test with owner test
2) add md5 auth for this user in pg_hba.conf like host test test
172.19.0.0/16 md5
3) compile test program src/postgres/src/test/examples/testlibpq.c
4) run test program with argument "host=postgres user=test password=wrong"
5) get double error on client side:
Connection to database failed: FATAL:  password authentication failed for
user "test"
FATAL:  password authentication failed for user "test"
6) and get double connection and double error on server side:
2021-05-25 16:49:42.868 +05 [46654] postgres(43832)
[unknown]@[unknown]/[unknown] LOG:  connection received: host=postgres
port=43832
2021-05-25 16:49:42.876 +05 [46654] postgres(43832) test@test/[unknown]
FATAL:  password authentication failed for user "test"
2021-05-25 16:49:42.876 +05 [46654] postgres(43832) test@test/[unknown]
DETAIL:  Password does not match for user "test".
    Connection matched pg_hba.conf line 99: "host test test 172.19.0.0/16
md5"
2021-05-25 16:49:42.877 +05 [46655] postgres(43834)
[unknown]@[unknown]/[unknown] LOG:  connection received: host=postgres
port=43834
2021-05-25 16:49:42.878 +05 [46655] postgres(43834) test@test/[unknown]
FATAL:  password authentication failed for user "test"
2021-05-25 16:49:42.878 +05 [46655] postgres(43834) test@test/[unknown]
DETAIL:  Password does not match for user "test".
    Connection matched pg_hba.conf line 99: "host test test 172.19.0.0/16 md5"