[Update] Prevent update.sh from updating docker-compose under Alpine Linux (#3708)

update.sh

@@ -482,6 +482,8 @@ fi
 
 if [[ ${NO_UPDATE_COMPOSE} == "y" ]]; then
   echo -e "\e[33mNot fetching latest docker-compose, please check for updates manually!\e[0m"
+elif [[ -e /etc/alpine-release ]]; then
+  echo -e "\e[33mNot fetching latest docker-compose, because you are using Alpine Linux without glibc support. Please update docker-compose via apk!\e[0m"
 else
   echo -e "\e[32mFetching new docker-compose version...\e[0m"
   sleep 1