[Koha] Create log4pearl.conf for old Koha instance?

[Prof. Lisandro Laura]

Hello!
I am getting the following message in the about page:
"You are missing the <log4perl_conf> entry in your koha-conf.xml file.
Please add it, pointing to the log4perl.conf file for your Koha
instance."

After a Google search I looked for the log4perl.conf file on my
server... but I can't find it. Do I have to create it in any way?
If not, Ijust need to add the following line in my
/etc/koha/sites/INSTANCE/koha-conf.xml ?
 <log4perl_conf>/etc/koha/log4perl.conf</log4perl_conf>

Thank you in advance...

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Koha: 17.05.02.000
Debian 8.9