For security reasons, and generally, it is best to create a more fine
grained group than plugdev. This way users that wish to tweak razer
devices don't have access to the entire plugdev group's permissions.
This is of course a breaking change.
This fixes:
```
systemd[1]: Started VictoriaMetrics time series database.
victoria-metrics[379550]: 2021-08-04T19:33:39.833Z panic VictoriaMetrics/lib/storage/partition.go:954 FATAL: unrecoverable error when merging small parts in the partition "/var/lib/victoriametrics/data/small/2021_08": cannot open source part for merging: cannot open metaindex file in stream mode: cannot open file "/var/lib/victoriametrics/data/small/2021_08/1228_1228_20210804184120.712_20210804184121.899_16982E83CD7A763A/metaindex.bin": open /var/lib/victoriametrics/data/small/2021_08/1228_1228_20210804184120.712_20210804184121.899_16982E83CD7A763A/metaindex.bin: too many open files
victoria-metrics[379550]: panic: FATAL: unrecoverable error when merging small parts in the partition "/var/lib/victoriametrics/data/small/2021_08": cannot open source part for merging: cannot open metaindex file in stream mode: cannot open file "/var/lib/victoriametrics/data/small/2021_08/1228_1228_20210804184120.712_20210804184121.899_16982E83CD7A763A/metaindex.bin": open /var/lib/victoriametrics/data/small/2021_08/1228_1228_20210804184120.712_20210804184121.899_16982E83CD7A763A/metaindex.bin: too many open files
victoria-metrics[379550]: goroutine 629 [running]:
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/logger.logMessage(0xbb3ea1, 0x5, 0xc001113800, 0x1e7, 0x4)
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/logger/logger.go:270 +0xc69
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/logger.logLevelSkipframes(0x1, 0xbb3ea1, 0x5, 0xbe3f8b, 0x4b, 0xc000bb3f88, 0x2, 0x2)
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/logger/logger.go:138 +0xd1
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/logger.logLevel(...)
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/logger/logger.go:130
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/logger.Panicf(...)
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/logger/logger.go:126
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/storage.(*partition).smallPartsMerger(0xc0014d7980)
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/storage/partition.go:954 +0x145
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/storage.(*partition).startMergeWorkers.func1(0xc0014d7980)
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/storage/partition.go:933 +0x2b
victoria-metrics[379550]: created by github.com/VictoriaMetrics/VictoriaMetrics/lib/storage.(*partition).startMergeWorkers
victoria-metrics[379550]: github.com/VictoriaMetrics/VictoriaMetrics/lib/storage/partition.go:932 +0x6c
systemd[1]: victoriametrics.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
systemd[1]: victoriametrics.service: Failed with result 'exit-code'.
systemd[1]: victoriametrics.service: Consumed 587ms CPU time, received 6.5K IP traffic, sent 1.7K IP traffic.
systemd[1]: victoriametrics.service: Scheduled restart job, restart counter is at 2064.
systemd[1]: Stopped VictoriaMetrics time series database.
systemd[1]: victoriametrics.service: Consumed 587ms CPU time, received 6.5K IP traffic, sent 1.7K IP traffic.
systemd[1]: Starting VictoriaMetrics time series database...
```
This option allows basic configuration of the compression technique
used in the backup script. Specifically it adds `none` and `zstd` as
new alternatives, keeping `gzip` as the default.
The service likes to write files uploaded by the user to the service
user's $HOME. In our case the hqplayerd user has no home directory,
since it's a system user, and regardless we'd like to keep the service's
state contained.
With this change the unit forces HOME to point to
/var/lib/hqplayer/home, which works around the issue.
