Return truethy when there are no data, but connection has been succeed

pywmcurrencies/pywmcurrencies.py

@@ -201,7 +201,7 @@ class SensorDockApp(wmdocklib.DockApp):
         if (self._data.get('_last_update') and
                 (now - self._data['_last_update']).seconds < 7500):
             # don't hammer npb service to often
-            return
+            return True
 
         for currency in self.conf.get('currencies'):
             url = (f'http://api.nbp.pl/api/exchangerates/rates/a/{currency}/'
@@ -214,7 +214,7 @@ class SensorDockApp(wmdocklib.DockApp):
             if response.status_code != 200:
                 print(f'error requesting data for currency "{currency} on '
                       f'time range between {start_date} and {end_date}')
-                return
+                return True
 
             self._data['_last_update'] = now
             result = response.json()