Merge pull request #2880 from nextcloud/skjnldsv-patch-1

fix: make sure etag is a string

Author: skjnldsv

apps/viewer/apps/viewer/src/utils/previewUtils.ts

@@ -27,7 +27,7 @@ export function getPreviewIfAny({ fileid, filename, previewUrl, hasPreview, davP
 		+ `&x=${Math.floor(screen.width * devicePixelRatio)}`
 		+ `&y=${Math.floor(screen.height * devicePixelRatio)}`
 		+ '&a=true'
-		+ (etag !== null ? `&etag=${etag.replace(/"/g, '')}` : '')
+		+ (etag ? `&etag=${String(etag).replace(/"/g, '')}` : '')
 
 	if (hasPreview) {
 		// TODO: find a nicer standard way of doing this?