Update app.py

app.py

@@ -115,7 +115,7 @@ def check_site_speed(url):
 
 def check_mobile_speed(url):
     try:
-        headers = {"Mozilla/5.0 (Android 11; Mobile; rv:90.0) Gecko/90.0 Firefox/90.0"}
+        headers = {"User-Agent": "Mozilla/5.0 (Android 11; Mobile; rv:90.0) Gecko/90.0 Firefox/90.0"}
         start_time = time.time()
         response = requests.get(url, headers=headers, timeout=10)
         response.raise_for_status()