Clear out the _cacheUUID too even though this is not strictly necessary.

Source/ASNetworkImageNode.mm

@@ -699,6 +699,7 @@
           //No longer in preload range, no point in setting the results (they won't be cleared in exit preload range)
           if (ASInterfaceStateIncludesPreload(self->_interfaceState) == NO) {
             self->_downloadIdentifier = nil;
+            self->_cacheUUID = nil;
             return;
           }