fixes #289 - issue warning log when geocoding fails

An exception with stack trace was generated when geocoding the Resource URL domain failed. This could happen quite often and pollutes logs. This commit makes this a warning with message from Exception.

GeoHealthCheck/util.py

@@ -200,7 +200,7 @@ def geocode(value, spatial_keyword_type='hostname'):
             lat, lon = content['lat'], content['lon']
         except Exception as err:  # skip storage
             msg = 'Could not derive coordinates: %s' % err
-            LOGGER.exception(msg)
+            LOGGER.warning(msg)
     return lat, lon