Fix panic on HTTP requests that fails reaching any provider

Author: wille

internal/http.go

@@ -156,9 +156,11 @@ func IncomingHttpHandler(ctx context.Context, endpoint *Endpoint, w http.Respons
 	res, provider, err := ProxyHTTP(ctx, endpoint, req, timing)
 
 	if err != nil {
+		if provider != nil {
 		for _, req := range req.Requests {
 			metrics.RecordFailedRequest(endpoint.Name, provider.Name, "http", req.Method)
 		}
+		}
 
 		if err == ErrNoProvidersAvailable {
 			log.Error("no providers available")