fix(rathole): enforce server-only mode; expose 2333; update docs

CloudronPackages/Rathole/Dockerfile

@@ -31,10 +31,9 @@ RUN mkdir -p /app/data && chown -R cloudron:cloudron /app/data
 USER cloudron
 
 ENV APP_PORT=3000 \
-    RATHOLE_MODE=server \
     RATHOLE_CONFIG_PATH=/app/data/rathole.toml
 
-EXPOSE 3000
+EXPOSE 3000 2333
 
 HEALTHCHECK --interval=30s --timeout=5s --start-period=20s --retries=3 \
   CMD curl -fsS http://127.0.0.1:${APP_PORT}/ || exit 1