Update Prometheus vendoring and simplify remote append code

ingester_client.go

@@ -77,8 +77,7 @@ func (c *IngesterClient) Append(ctx context.Context, samples []*model.Sample) er
 		req.Timeseries = append(req.Timeseries, ts)
 	}
 
-	var resp remote.WriteResponse
-	return c.doRequest(ctx, "/push", req, &resp, true)
+	return c.doRequest(ctx, "/push", req, nil, true)
 }
 
 // Query implements Querier.

server.go

@@ -126,22 +126,6 @@ func AppenderHandler(appender SampleAppender) http.Handler {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
-
-		respBuf, err := proto.Marshal(&remote.WriteResponse{})
-		if err != nil {
-			log.Errorf("marshall err: %v", err)
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-
-		if _, err := snappy.NewWriter(w).Write(respBuf); err != nil {
-			log.Errorf("write err: %v", err)
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-
-		w.Header().Add("Content-Encoding", "snappy")
-		w.WriteHeader(http.StatusOK)
 	})
 }