Merge branch 'doc-evn-ssh-or-sshd' into 'master'

Clarify it may be ssh

See merge request gitlab-org/gitlab-ee!3598

doc/administration/operations/speed_up_ssh.md

@@ -43,9 +43,13 @@ AuthorizedKeysCommand /opt/gitlab-shell/authorized_keys %u %k
 AuthorizedKeysCommandUser git
 ```
 
-Reload the sshd service:
+Reload OpenSSH:
 
-```
+```bash
+# Debian or Ubuntu installations
+sudo service ssh reload
+
+# CentOS installations
 sudo service sshd reload
 ```