Require HTTP 200 from curl before using IP

Replace simple curl+trim checks with a response+http_code parse to ensure the remote URL returns HTTP 200 and a non-empty body before assigning server_ip. Changes applied to install.sh, update.sh and x-ui.sh: use curl -w to append the status code, extract http_code and ip_result, and only set server_ip when http_code == 200 and ip_result is non-empty. This makes the IP discovery more robust against error pages or partial responses while keeping the existing timeout behavior.

update.sh

@@ -687,8 +687,11 @@ config_after_update() {
     )
     local server_ip=""
     for ip_address in "${URL_lists[@]}"; do
-        server_ip=$(${curl_bin} -s --max-time 3 "${ip_address}" 2>/dev/null | tr -d '[:space:]')
-        if [[ -n "${server_ip}" ]]; then
+        local response=$(curl -s -w "\n%{http_code}" --max-time 3 "${ip_address}" 2>/dev/null)
+        local http_code=$(echo "$response" | tail -n1)
+        local ip_result=$(echo "$response" | head -n-1 | tr -d '[:space:]')
+        if [[ "${http_code}" == "200" && -n "${ip_result}" ]]; then
+            server_ip="${ip_result}"
             break
         fi
     done