Reworked attribution handling

src/ol/renderer/canvas/imagelayer.js

@@ -134,7 +134,6 @@ ol.renderer.canvas.ImageLayer.prototype.prepareFrame = function(frameState, laye
         0,
         -viewCenter[0], -viewCenter[1]);
 
-    this.updateAttributions(frameState.attributions, image.getAttributions());
     this.updateLogos(frameState, imageSource);
     this.renderedResolution = imageResolution * pixelRatio / imagePixelRatio;
   }

src/ol/renderer/canvas/vectorlayer.js

@@ -261,8 +261,6 @@ ol.renderer.canvas.VectorLayer.prototype.prepareFrame = function(frameState, lay
   var vectorLayer = /** @type {ol.layer.Vector} */ (this.getLayer());
   var vectorSource = vectorLayer.getSource();
 
-  this.updateAttributions(
-      frameState.attributions, vectorSource.getAttributions());
   this.updateLogos(frameState, vectorSource);
 
   var animating = frameState.viewHints[ol.ViewHint.ANIMATING];