RATP: Use cache when API is not reachable

modules/ratp.py

@@ -83,9 +83,12 @@ class IDFMAPI:
         if statinfo is None or datetime.fromtimestamp(statinfo.st_mtime, tz=timezone.utc) + timedelta(minutes=self.cache_time) < datetime.now(tz=timezone.utc):
             # Do the request and save it
             req = urllib.request.Request(self.baseurl + "/general-message?LineRef=STIF:Line::" + IDFMAPI.lines[mode][line] + ":", headers={'apikey': self.apikey})
-            with urllib.request.urlopen(req) as f:
-                with open(cache_file, 'wb') as fd:
-                    fd.write(f.read())
+            try:
+                with urllib.request.urlopen(req) as f:
+                    with open(cache_file, 'wb') as fd:
+                        fd.write(f.read())
+            except ConnectionResetError:
+                pass
 
         # Retrieve cached data
         res = {}