Description: The systemd.service file of `/usr/lib/systemd/system/tor.service` has been misconfigured with appropriate user omitted. This misconfiguration leads to failures in starting the corresponding service.

Additional info:
* package version(s): 0.4.4.5-4
* config and/or log files etc.
The log of `Tor.service` from system journal:
```
Oct 18 11:41:42 ArchPad tor[1681]: Oct 18 04:41:42.326 [notice] Tor 0.4.4.5 running on Linux with Libevent 2.1.12-stable, OpenSSL 1.1.1h, Zlib 1.2.11, Liblzma 5.2.5, and Libzstd 1.4.5.
Oct 18 11:41:42 ArchPad tor[1681]: Oct 18 04:41:42.326 [notice] Tor can't help you if you use it wrong! Learn how to be safe at https://www.torproject.org/download/download#warning
Oct 18 11:41:42 ArchPad tor[1681]: Oct 18 04:41:42.326 [notice] Read configuration file "/etc/tor/torrc".
Oct 18 11:41:42 ArchPad tor[1681]: Oct 18 04:41:42.333 [warn] /var/lib/tor is not owned by this user (root, 0) but by tor (43). Perhaps you are running Tor as the wrong user?
Oct 18 11:41:42 ArchPad tor[1681]: Oct 18 04:41:42.333 [warn] Failed to parse/validate config: Couldn't access private data directory "/var/lib/tor"
Oct 18 11:41:42 ArchPad tor[1681]: Oct 18 04:41:42.333 [err] Reading config failed--see warnings above.
```

Content of `/usr/lib/systemd/system/tor.service`:
```
# tor.service -- this systemd configuration file for Tor sets up a
# relatively conservative, hardened Tor service. You may need to
# edit it if you are making changes to your Tor configuration that it
# does not allow. Package maintainers: this should be a starting point
# for your tor.service; it is not the last point.

[Unit]
Description=Anonymizing overlay network for TCP
After=syslog.target network.target nss-lookup.target

[Service]
Type=notify
NotifyAccess=all
ExecStartPre=/usr/bin/tor -f /etc/tor/torrc --verify-config
ExecStart=/usr/bin/tor -f /etc/tor/torrc
ExecReload=/bin/kill -HUP ${MAINPID}
KillSignal=SIGINT
TimeoutSec=60
Restart=on-failure
WatchdogSec=1m
LimitNOFILE=32768

# Hardening
PrivateTmp=yes
PrivateDevices=yes
ProtectHome=yes
ProtectSystem=full
ReadOnlyDirectories=/
ReadWriteDirectories=-/var/lib/tor
ReadWriteDirectories=-/var/log/tor
NoNewPrivileges=yes
CapabilityBoundingSet=CAP_SETUID CAP_SETGID CAP_NET_BIND_SERVICE CAP_DAC_READ_SEARCH

[Install]
WantedBy=multi-user.target
```

Steps to reproduce:
1. Install/Upgrade community/tor package to the version above
2. Restart tor.service