MapRoulette: Add error logging

This makes it easier to debug the error cases when the MR API returns an error.

modules/ui/maproulette_details.js

@@ -230,6 +230,7 @@ export function uiMapRouletteDetails(context) {
           highlightFeature(osmId);
         });
     }).catch(e => {
+      console.error('error_loading_task_details:', e);
       const selection = details.selectAll('.qa-details-subsection');
       selection.html(''); // replace contents
       const error = selection