fix invalid random pattern for creation of groups (only lowercase + number allowed)

root/etc/cont-init.d/50-gid-video

@@ -11,7 +11,7 @@ do
 		if [ ! "${VIDEO_GID}" == '0' ]; then
 			VIDEO_NAME=$(getent group "${VIDEO_GID}" | awk -F: '{print $1}')
 			if [ -z "${VIDEO_NAME}" ]; then
-				VIDEO_NAME="video$(head /dev/urandom | tr -dc 'a-zA-Z0-9' | head -c8)"
+				VIDEO_NAME="video$(head /dev/urandom | tr -dc 'a-za-z0-9' | head -c8)"
 				groupadd "$VIDEO_NAME"
 				groupmod -g "$VIDEO_GID" "$VIDEO_NAME"
 			fi
@@ -23,4 +23,4 @@ done
 
 if [ -n "${FILES}" ] && [ ! -f "/groupadd" ]; then
 	usermod -a -G root abc
-fi
+fi