Clean up *.log.1 files during 6.6-to-6.7 upgrade

doc/update/6.6-to-6.7.md

@@ -64,6 +64,10 @@ sudo cp lib/support/init.d/gitlab /etc/init.d/gitlab
 # Update the logrotate configuration (keep logs for 90 days instead of 52 weeks)
 sudo cp lib/support/logrotate/gitlab /etc/logrotate.d/gitlab
+# Compress existing .log.1 files because we turned off delaycompress in logrotate
+sudo -u git -H gzip /home/git/gitlab/log/*.log.1
+sudo -u git -H gzip /home/git/gitlab-shell/gitlab-shell.log.1
+
 # Close access to gitlab-satellites for others
 sudo chmod u+rwx,g+rx,o-rwx /home/git/gitlab-satellites
 ```