service-worker: bugfix for uncaught Promise rejection in background no-stash fetches (ref. #11)

service-worker.js

@@ -477,7 +477,9 @@ let getResourceThroughLibResilient = (request, clientId, useStashed=true, doStas
             self.log('service-worker', 'starting background no-stashed fetch for:', url);
             // event.waitUntil?
             // https://stackoverflow.com/questions/37902441/what-does-event-waituntil-do-in-service-worker-and-why-is-it-needed/37906330#37906330
-            getResourceThroughLibResilient(request, clientId, false, true, response.clone())
+            getResourceThroughLibResilient(request, clientId, false, true, response.clone()).catch((e)=>{
+                self.log('service-worker', 'background no-stashed fetch failed for:', url);
+            })
             // return the response so that stuff can keep happening
             return response