BUG #17192: The csvlog is corrupted

The following bug has been logged on the website:

Bug reference:      17192
Logged by:          Jef Vervecken
Email address:      jef.vervecken@ubench.com
PostgreSQL version: 13.4
Operating system:   Ubuntu 18.04
Description:

The content of the csvlog file seems to be corrupted. Most lines are correct
but some lines seems to be merged.
I'll put 3 lines here, first and third lines are correct, but the second
line is corrupted.  This result ofcourse in errors when I try to import the
logs into a table via the copy command:

line 1:
2021-09-13 13:03:17.132
CEST,"postgres","ubenchdb",5361,"10.0.10.109:50726",613f2ff5.14f1,1,"idle",2021-09-13
13:03:17 CEST,3/0,0,LOG,08006,"could not receive data from client:
Connection reset by peer",,,,,,,,,"postgres_fdw","client backend"

Line 2:
2021-09-13 13:03:17.193
CEST,"postgres","ubenchdb",5362,"10.0.10.109:50728",613f2ff5.14f2,1,"idle",2021-09-13
13:03:17 CEST,3/0,0,LOG,08006,"could not receive data from client:
Connection reset by peer",,,,,,t: Connection reset by
peer",,,,,,,,,"postgres_fdw","client backend"

Line 3:
2021-09-13 13:04:09.423
CEST,"postgres","ubenchdb",32291,"10.0.10.109:33276",613f3029.7e23,1,"idle",2021-09-13
13:04:09 CEST,79/0,0,LOG,08006,"could not receive data from client:
Connection reset by peer",,,,,,,,,"postgres_fdw","client backend"