Missing a newline on /etc/sudoers.d/telegraf_ovs

[Marcelo Subtil Marcal]

In a newly deployed focal-yoga cloud using telegraph (stable/57), the octavia/leader unit gets stuck in an error state (hook failed: "identity-service-relation-changed").

When trying to run debug-hook, I got:

```
$ juju debug-hook octavia/2
>>> /etc/sudoers.d/telegraf_ovs: syntax error near line 10 <<<
sudo: parse error in /etc/sudoers.d/telegraf_ovs near line 10
sudo: no valid sudoers sources found, quitting
sudo: unable to initialize policy plugin
Connection to 192.168.30.237 closed.
```

Looking at the /etc/sudoers.d/telegraf_ovs file I found out that there is a missing newline at the end of the file:

```
$ juju run -u octavia/2 -- cat /etc/sudoers.d/telegraf_ovs
Defaults:telegraf !requiretty
Cmnd_Alias OVSOFCTL = /usr/bin/ovs-ofctl
Cmnd_Alias OVSVSCTL = /usr/bin/ovs-vsctl
Cmnd_Alias OVSAPPCTL = /usr/bin/ovs-appctl
telegraf ALL = (root) NOPASSWD: OVSOFCTL
telegraf ALL = (root) NOPASSWD: OVSVSCTL
telegraf ALL = (root) NOPASSWD: OVSAPPCTL
Defaults!OVSOFCTL !logfile, !syslog, !pam_session
Defaults!OVSVSCTL !logfile, !syslog, !pam_session
Defaults!OVSAPPCTL !logfile, !syslog, !pam_sessionubuntu@sdtpdc41s100001:~/deploy$
```

Workaround:

```
juju run --application telegraf -- 'echo "" >> /etc/sudoers.d/telegraf_ovs'
````

[Pedro Guimarães (pguimaraes)]

Escalating this issue as field-critical, as it is a blocker for the deployment.

[Eric Chen (eric-chen)]

Yes, we found this bug yesterday and rollback to revision 54 on stable channel.
https://charmhub.io/telegraf

Please downgrade it for the solution. We will fix this bug asap.

thanks!