Docker/Alpine: Remove USB group

The USB group has been removed from upstream alpine in commit
bb00d0e4f345 ("main/alpine-baselayout: remove mem and usb group") which
was a fixup on commit
f16d0754d601 ("main/alpine-baselayout: remove unused/moved users and groups")

Lets remove it here as well as we cannot join the group any longer.

Besides, device access is probably better managed with host specific
udev rules.

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>

Author: oliv3r

Containerfile.alpine

@@ -116,7 +116,6 @@ RUN apk add --no-cache \
     addgroup -S 'tvheadend' && \
     adduser -D -G 'tvheadend' -h '/var/lib/tvheadend' -s '/bin/nologin' -S 'tvheadend' && \
     adduser 'tvheadend' 'audio' && \
-    adduser 'tvheadend' 'usb' && \
     adduser 'tvheadend' 'video' && \
     install -d -m 775 -g 'tvheadend' -o 'tvheadend' '/var/lib/tvheadend/recordings' && \
     install -d -m 775 -g 'tvheadend' -o 'tvheadend' '/var/log/tvheadend'