FreeBSD 12.2 Jail (under TrueNAS jails) fails to install as a service: `/usr/local/etc/rc.d/AdGuardHome: no such file or directory`

### Prerequisites

- [x] I am running the latest version
- [x] I checked the documentation and found no answer
- [x] I checked to make sure that this issue has not already been filed

### Issue Details
* **Version of AdGuard Home server:**
* AdGuard Home, version v0.105.2, channel release, arch freebsd amd64
* **How did you install AdGuard Home:**
* curl sh script
* **Operating system and version:**
* TrueNAS Jail running FreeBSD
```
root@AdGuardHome:/opt/AdGuardHome # cat /etc/os-release
NAME=FreeBSD
VERSION=12.2-RELEASE-p5
VERSION_ID=12.2
ID=freebsd
ANSI_COLOR="0;31"
PRETTY_NAME="FreeBSD 12.2-RELEASE-p5"
CPE_NAME=cpe:/o:freebsd:freebsd:12.2
HOME_URL=https://FreeBSD.org/
BUG_REPORT_URL=https://bugs.FreeBSD.org/

```
### Expected Behavior
AsGuardHome successfully installs

### Actual Behavior
```
root@AdGuardHome:~ # curl -sSL https://raw.githubusercontent.com/AdguardTeam/AdGuardHome/master/scripts/install.sh | sh
[info] Starting AdGuard Home installation script
[info] Channel release
[info] Script called with root privileges
[info] AdGuard Home will be installed to /opt/AdGuardHome
[info] Downloading package from https://static.adguard.com/adguardhome/release/AdGuardHome_freebsd_amd64.tar.gz -> AdGuardHome_freebsd_amd64.tar.gz
[info] Unpacking package from AdGuardHome_freebsd_amd64.tar.gz -> /opt
2021/04/05 21:12:03 [info] Service control action: install
2021/04/05 21:12:03 [fatal] Failed to install AdGuard Home service: open /usr/local/etc/rc.d/AdGuardHome: no such file or directory
[error] Cannot install AdGuardHome as a service
```

The rc.d script is not found\installed

### Additional Information
The path `/usr/local/etc/` has no `rc.d` subdir.
I successfuly managed to spinup AdGuardHome as a service by manually creating the service thanks to this forum post: https://forums.freebsd.org/threads/guide-how-to-install-adguardhome-on-freebsd.75496/