[FIX] BookOrbit: add missing restore_backup during update (#15881)

- Otherwise the `.env` file is not restored and the sed command fails

ct/bookorbit.sh

@@ -53,6 +53,7 @@ function update_script() {
     mkdir -p /opt/bookorbit/server/migrations
     cp -r /opt/bookorbit/server/src/db/migrations/. /opt/bookorbit/server/migrations/
     chmod +x /opt/bookorbit/server/bin/kepubify/*
+    restore_backup
     APP_VER=$(cat ~/.bookorbit)
     sed -i "s/^APP_VERSION=.*/APP_VERSION=v$APP_VER/" /opt/bookorbit/.env
     msg_ok "Rebuilt Application"