Always set the tile url.

This avoids false positives in the url check in CacheWrite::cache when the CacheRead control is also active.

lib/OpenLayers/Control/CacheRead.js

@@ -113,10 +113,9 @@ OpenLayers.Control.CacheRead = OpenLayers.Class(OpenLayers.Control, {
             var tile = evt.tile,
                 dataURI = window.localStorage.getItem("olCache_" + tile.url);
             if (dataURI) {
+                tile.url = dataURI;
                 if (evt.type === "tileerror") {
                     tile.setImgSrc(dataURI);
-                } else {
-                    tile.url = dataURI;
                 }
             }
         }